fix(core): symmetric bandar thresholds; bandar needs all investors

- Basis points truncate toward zero instead of flooring, so a reading of -4.9952% stays neutral like its mirror image and -14.9952% stays distribution; tests cover both signs at both thresholds through bandar_tier. Goldens move by the rounding (BBCA top 5: -2426 -> -2425). - With one investor side selected the summary has no total to weigh brokers against, so bandar and analyze_bandar reject it (INVALIDINPUT) instead of reading every tier as missing. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01V3syn2fN2LNo5pvTSqc6eh
2026-11-07 01:35:36 +00:00 · 2026-10-18 05:39:05 +00:00 · 2026-10-18 05:39:05 +00:00 · 4c2f0acff3
commit 4c2f0acff3
parent 970da26a0e
13 changed files with 73 additions and 18 deletions
--- a/crates/idx-cli/src/cli/stocks.rs
+++ b/crates/idx-cli/src/cli/stocks.rs
@ -206,7 +206,8 @@ does not show broker codes during trading. Without dates, the latest session wit
        long_about = "Bandarmology from the broker summary: the top 1, 3, 5 and 10 buyers' value \
 against the same number of sellers', as a share of value traded, with a signal from big \
 accumulation to big distribution. Several symbols give a screen ranked by the headline tier \
-(at most 100, one request each). A heuristic over end-of-day broker codes, not advice.",
+(at most 100, one request each). Counts all investors (`--investor` must be `all`). A \
+heuristic over end-of-day broker codes, not advice.",
        after_help = "Examples:\n  idx stocks bandar BBCA\n  idx stocks bandar BBCA --from 2026-10-12 --to 2026-10-16 --top 3\n  idx stocks bandar BBCA,BBRI,BMRI,TLKM\n  idx stocks screen --filter high-volume | jq -r '.[].symbol' | idx stocks bandar -"
    )]
    Bandar {
--- a/crates/idx-cli/tests/cli.rs
+++ b/crates/idx-cli/tests/cli.rs
@ -2632,9 +2632,9 @@ fn bandar_reads_the_broker_summary_tiers() {
    let top5 = &report["tiers"][2];
    assert_eq!(top5["buy_value"], 2_939_500_000_000_i64);
    assert_eq!(top5["sell_value"], 4_540_400_000_000_i64);
-    assert_eq!(top5["imbalance_bps"], -2426);
+    assert_eq!(top5["imbalance_bps"], -2425);
    assert_eq!(report["top"], 5);
-    assert_eq!(report["imbalance_bps"], -2426);
+    assert_eq!(report["imbalance_bps"], -2425);
    assert_eq!(report["signal"], "big_distribution");
    assert_eq!(
        report["both_sides"],
@ -2716,6 +2716,10 @@ fn bandar_errors_follow_the_output_contract() {
            ],
            "INVALIDINPUT",
        ),
+        (
+            vec!["BBCA".to_string(), "--investor".into(), "foreign".into()],
+            "INVALIDINPUT",
+        ),
    ] {
        let mut cmd = mock_bin("bandar-errors");
        cmd.args(["-o", "json", "stocks", "bandar"]).args(&args);
--- a/crates/idx-cli/tests/golden/stocks-bandar-screen.json.golden
+++ b/crates/idx-cli/tests/golden/stocks-bandar-screen.json.golden
@ -1,4 +1,4 @@
 exit: 0
 --- stdout
-[{"symbol":"BBRI.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-1749,"tiers":[{"top":1,"buy_value":504300000000,"sell_value":1000000000000,"imbalance_value":-495700000000,"imbalance_bps":-1503,"buy_share_bps":1528,"sell_share_bps":3030,"buy_average":2709,"sell_average":2716,"signal":"big_distribution"},{"top":3,"buy_value":1262700000000,"sell_value":1839600000000,"imbalance_value":-576900000000,"imbalance_bps":-1749,"buy_share_bps":3826,"sell_share_bps":5574,"buy_average":2715,"sell_average":2705,"signal":"big_distribution"},{"top":5,"buy_value":1737100000000,"sell_value":2283000000000,"imbalance_value":-545900000000,"imbalance_bps":-1655,"buy_share_bps":5263,"sell_share_bps":6918,"buy_average":2711,"sell_average":2707,"signal":"big_distribution"},{"top":10,"buy_value":2337100000000,"sell_value":2773100000000,"imbalance_value":-436000000000,"imbalance_bps":-1322,"buy_share_bps":7082,"sell_share_bps":8403,"buy_average":2709,"sell_average":2708,"signal":"distribution"}],"total_value":3300000000000,"average_price":2708,"foreign_net_value":-1100000000000,"foreign_net_bps":-3334,"both_sides":["AK","CC","NI","XL","YP","YU"],"rounded":true},{"symbol":"TLKM.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-1994,"tiers":[{"top":1,"buy_value":381600000000,"sell_value":721600000000,"imbalance_value":-340000000000,"imbalance_bps":-1546,"buy_share_bps":1734,"sell_share_bps":3280,"buy_average":1960,"sell_average":1933,"signal":"big_distribution"},{"top":3,"buy_value":949100000000,"sell_value":1387700000000,"imbalance_value":-438600000000,"imbalance_bps":-1994,"buy_share_bps":4314,"sell_share_bps":6307,"buy_average":1939,"sell_average":1931,"signal":"big_distribution"},{"top":5,"buy_value":1341400000000,"sell_value":1722500000000,"imbalance_value":-381100000000,"imbalance_bps":-1733,"buy_share_bps":6097,"sell_share_bps":7829,"buy_average":1938,"sell_average":1932,"signal":"big_distribution"},{"top":10,"buy_value":1869600000000,"sell_value":1992600000000,"imbalance_value":-123000000000,"imbalance_bps":-560,"buy_share_bps":8498,"sell_share_bps":9057,"buy_average":1932,"sell_average":1930,"signal":"distribution"}],"total_value":2200000000000,"average_price":1931,"foreign_net_value":-90200000000,"foreign_net_bps":-410,"both_sides":["AK","BK","CC","KZ","MG","XL","YP","YU","ZP"],"rounded":true},{"symbol":"BBCA.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-2914,"tiers":[{"top":1,"buy_value":841200000000,"sell_value":2200000000000,"imbalance_value":-1358800000000,"imbalance_bps":-2059,"buy_share_bps":1274,"sell_share_bps":3333,"buy_average":5191,"sell_average":5211,"signal":"big_distribution"},{"top":3,"buy_value":1984700000000,"sell_value":3907600000000,"imbalance_value":-1922900000000,"imbalance_bps":-2914,"buy_share_bps":3007,"sell_share_bps":5920,"buy_average":5212,"sell_average":5233,"signal":"big_distribution"},{"top":5,"buy_value":2939500000000,"sell_value":4540400000000,"imbalance_value":-1600900000000,"imbalance_bps":-2426,"buy_share_bps":4453,"sell_share_bps":6879,"buy_average":5211,"sell_average":5229,"signal":"big_distribution"},{"top":10,"buy_value":4477100000000,"sell_value":5551800000000,"imbalance_value":-1074700000000,"imbalance_bps":-1629,"buy_share_bps":6783,"sell_share_bps":8411,"buy_average":5213,"sell_average":5228,"signal":"big_distribution"}],"total_value":6600000000000,"average_price":5228,"foreign_net_value":-2300000000000,"foreign_net_bps":-3485,"both_sides":["AK","CC","MG","XL","YU","ZP"],"rounded":true}]
+[{"symbol":"BBRI.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-1748,"tiers":[{"top":1,"buy_value":504300000000,"sell_value":1000000000000,"imbalance_value":-495700000000,"imbalance_bps":-1502,"buy_share_bps":1528,"sell_share_bps":3030,"buy_average":2709,"sell_average":2716,"signal":"big_distribution"},{"top":3,"buy_value":1262700000000,"sell_value":1839600000000,"imbalance_value":-576900000000,"imbalance_bps":-1748,"buy_share_bps":3826,"sell_share_bps":5574,"buy_average":2715,"sell_average":2705,"signal":"big_distribution"},{"top":5,"buy_value":1737100000000,"sell_value":2283000000000,"imbalance_value":-545900000000,"imbalance_bps":-1654,"buy_share_bps":5263,"sell_share_bps":6918,"buy_average":2711,"sell_average":2707,"signal":"big_distribution"},{"top":10,"buy_value":2337100000000,"sell_value":2773100000000,"imbalance_value":-436000000000,"imbalance_bps":-1321,"buy_share_bps":7082,"sell_share_bps":8403,"buy_average":2709,"sell_average":2708,"signal":"distribution"}],"total_value":3300000000000,"average_price":2708,"foreign_net_value":-1100000000000,"foreign_net_bps":-3333,"both_sides":["AK","CC","NI","XL","YP","YU"],"rounded":true},{"symbol":"TLKM.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-1993,"tiers":[{"top":1,"buy_value":381600000000,"sell_value":721600000000,"imbalance_value":-340000000000,"imbalance_bps":-1545,"buy_share_bps":1734,"sell_share_bps":3280,"buy_average":1960,"sell_average":1933,"signal":"big_distribution"},{"top":3,"buy_value":949100000000,"sell_value":1387700000000,"imbalance_value":-438600000000,"imbalance_bps":-1993,"buy_share_bps":4314,"sell_share_bps":6307,"buy_average":1939,"sell_average":1931,"signal":"big_distribution"},{"top":5,"buy_value":1341400000000,"sell_value":1722500000000,"imbalance_value":-381100000000,"imbalance_bps":-1732,"buy_share_bps":6097,"sell_share_bps":7829,"buy_average":1938,"sell_average":1932,"signal":"big_distribution"},{"top":10,"buy_value":1869600000000,"sell_value":1992600000000,"imbalance_value":-123000000000,"imbalance_bps":-559,"buy_share_bps":8498,"sell_share_bps":9057,"buy_average":1932,"sell_average":1930,"signal":"distribution"}],"total_value":2200000000000,"average_price":1931,"foreign_net_value":-90200000000,"foreign_net_bps":-410,"both_sides":["AK","BK","CC","KZ","MG","XL","YP","YU","ZP"],"rounded":true},{"symbol":"BBCA.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-2913,"tiers":[{"top":1,"buy_value":841200000000,"sell_value":2200000000000,"imbalance_value":-1358800000000,"imbalance_bps":-2058,"buy_share_bps":1274,"sell_share_bps":3333,"buy_average":5191,"sell_average":5211,"signal":"big_distribution"},{"top":3,"buy_value":1984700000000,"sell_value":3907600000000,"imbalance_value":-1922900000000,"imbalance_bps":-2913,"buy_share_bps":3007,"sell_share_bps":5920,"buy_average":5212,"sell_average":5233,"signal":"big_distribution"},{"top":5,"buy_value":2939500000000,"sell_value":4540400000000,"imbalance_value":-1600900000000,"imbalance_bps":-2425,"buy_share_bps":4453,"sell_share_bps":6879,"buy_average":5211,"sell_average":5229,"signal":"big_distribution"},{"top":10,"buy_value":4477100000000,"sell_value":5551800000000,"imbalance_value":-1074700000000,"imbalance_bps":-1628,"buy_share_bps":6783,"sell_share_bps":8411,"buy_average":5213,"sell_average":5228,"signal":"big_distribution"}],"total_value":6600000000000,"average_price":5228,"foreign_net_value":-2300000000000,"foreign_net_bps":-3484,"both_sides":["AK","CC","MG","XL","YU","ZP"],"rounded":true}]
 --- stderr
--- a/crates/idx-cli/tests/golden/stocks-bandar-screen.jsonl.golden
+++ b/crates/idx-cli/tests/golden/stocks-bandar-screen.jsonl.golden
@ -1,6 +1,6 @@
 exit: 0
 --- stdout
-{"symbol":"BBRI.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-1749,"tiers":[{"top":1,"buy_value":504300000000,"sell_value":1000000000000,"imbalance_value":-495700000000,"imbalance_bps":-1503,"buy_share_bps":1528,"sell_share_bps":3030,"buy_average":2709,"sell_average":2716,"signal":"big_distribution"},{"top":3,"buy_value":1262700000000,"sell_value":1839600000000,"imbalance_value":-576900000000,"imbalance_bps":-1749,"buy_share_bps":3826,"sell_share_bps":5574,"buy_average":2715,"sell_average":2705,"signal":"big_distribution"},{"top":5,"buy_value":1737100000000,"sell_value":2283000000000,"imbalance_value":-545900000000,"imbalance_bps":-1655,"buy_share_bps":5263,"sell_share_bps":6918,"buy_average":2711,"sell_average":2707,"signal":"big_distribution"},{"top":10,"buy_value":2337100000000,"sell_value":2773100000000,"imbalance_value":-436000000000,"imbalance_bps":-1322,"buy_share_bps":7082,"sell_share_bps":8403,"buy_average":2709,"sell_average":2708,"signal":"distribution"}],"total_value":3300000000000,"average_price":2708,"foreign_net_value":-1100000000000,"foreign_net_bps":-3334,"both_sides":["AK","CC","NI","XL","YP","YU"],"rounded":true}
-{"symbol":"TLKM.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-1994,"tiers":[{"top":1,"buy_value":381600000000,"sell_value":721600000000,"imbalance_value":-340000000000,"imbalance_bps":-1546,"buy_share_bps":1734,"sell_share_bps":3280,"buy_average":1960,"sell_average":1933,"signal":"big_distribution"},{"top":3,"buy_value":949100000000,"sell_value":1387700000000,"imbalance_value":-438600000000,"imbalance_bps":-1994,"buy_share_bps":4314,"sell_share_bps":6307,"buy_average":1939,"sell_average":1931,"signal":"big_distribution"},{"top":5,"buy_value":1341400000000,"sell_value":1722500000000,"imbalance_value":-381100000000,"imbalance_bps":-1733,"buy_share_bps":6097,"sell_share_bps":7829,"buy_average":1938,"sell_average":1932,"signal":"big_distribution"},{"top":10,"buy_value":1869600000000,"sell_value":1992600000000,"imbalance_value":-123000000000,"imbalance_bps":-560,"buy_share_bps":8498,"sell_share_bps":9057,"buy_average":1932,"sell_average":1930,"signal":"distribution"}],"total_value":2200000000000,"average_price":1931,"foreign_net_value":-90200000000,"foreign_net_bps":-410,"both_sides":["AK","BK","CC","KZ","MG","XL","YP","YU","ZP"],"rounded":true}
-{"symbol":"BBCA.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-2914,"tiers":[{"top":1,"buy_value":841200000000,"sell_value":2200000000000,"imbalance_value":-1358800000000,"imbalance_bps":-2059,"buy_share_bps":1274,"sell_share_bps":3333,"buy_average":5191,"sell_average":5211,"signal":"big_distribution"},{"top":3,"buy_value":1984700000000,"sell_value":3907600000000,"imbalance_value":-1922900000000,"imbalance_bps":-2914,"buy_share_bps":3007,"sell_share_bps":5920,"buy_average":5212,"sell_average":5233,"signal":"big_distribution"},{"top":5,"buy_value":2939500000000,"sell_value":4540400000000,"imbalance_value":-1600900000000,"imbalance_bps":-2426,"buy_share_bps":4453,"sell_share_bps":6879,"buy_average":5211,"sell_average":5229,"signal":"big_distribution"},{"top":10,"buy_value":4477100000000,"sell_value":5551800000000,"imbalance_value":-1074700000000,"imbalance_bps":-1629,"buy_share_bps":6783,"sell_share_bps":8411,"buy_average":5213,"sell_average":5228,"signal":"big_distribution"}],"total_value":6600000000000,"average_price":5228,"foreign_net_value":-2300000000000,"foreign_net_bps":-3485,"both_sides":["AK","CC","MG","XL","YU","ZP"],"rounded":true}
+{"symbol":"BBRI.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-1748,"tiers":[{"top":1,"buy_value":504300000000,"sell_value":1000000000000,"imbalance_value":-495700000000,"imbalance_bps":-1502,"buy_share_bps":1528,"sell_share_bps":3030,"buy_average":2709,"sell_average":2716,"signal":"big_distribution"},{"top":3,"buy_value":1262700000000,"sell_value":1839600000000,"imbalance_value":-576900000000,"imbalance_bps":-1748,"buy_share_bps":3826,"sell_share_bps":5574,"buy_average":2715,"sell_average":2705,"signal":"big_distribution"},{"top":5,"buy_value":1737100000000,"sell_value":2283000000000,"imbalance_value":-545900000000,"imbalance_bps":-1654,"buy_share_bps":5263,"sell_share_bps":6918,"buy_average":2711,"sell_average":2707,"signal":"big_distribution"},{"top":10,"buy_value":2337100000000,"sell_value":2773100000000,"imbalance_value":-436000000000,"imbalance_bps":-1321,"buy_share_bps":7082,"sell_share_bps":8403,"buy_average":2709,"sell_average":2708,"signal":"distribution"}],"total_value":3300000000000,"average_price":2708,"foreign_net_value":-1100000000000,"foreign_net_bps":-3333,"both_sides":["AK","CC","NI","XL","YP","YU"],"rounded":true}
+{"symbol":"TLKM.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-1993,"tiers":[{"top":1,"buy_value":381600000000,"sell_value":721600000000,"imbalance_value":-340000000000,"imbalance_bps":-1545,"buy_share_bps":1734,"sell_share_bps":3280,"buy_average":1960,"sell_average":1933,"signal":"big_distribution"},{"top":3,"buy_value":949100000000,"sell_value":1387700000000,"imbalance_value":-438600000000,"imbalance_bps":-1993,"buy_share_bps":4314,"sell_share_bps":6307,"buy_average":1939,"sell_average":1931,"signal":"big_distribution"},{"top":5,"buy_value":1341400000000,"sell_value":1722500000000,"imbalance_value":-381100000000,"imbalance_bps":-1732,"buy_share_bps":6097,"sell_share_bps":7829,"buy_average":1938,"sell_average":1932,"signal":"big_distribution"},{"top":10,"buy_value":1869600000000,"sell_value":1992600000000,"imbalance_value":-123000000000,"imbalance_bps":-559,"buy_share_bps":8498,"sell_share_bps":9057,"buy_average":1932,"sell_average":1930,"signal":"distribution"}],"total_value":2200000000000,"average_price":1931,"foreign_net_value":-90200000000,"foreign_net_bps":-410,"both_sides":["AK","BK","CC","KZ","MG","XL","YP","YU","ZP"],"rounded":true}
+{"symbol":"BBCA.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":3,"signal":"big_distribution","imbalance_bps":-2913,"tiers":[{"top":1,"buy_value":841200000000,"sell_value":2200000000000,"imbalance_value":-1358800000000,"imbalance_bps":-2058,"buy_share_bps":1274,"sell_share_bps":3333,"buy_average":5191,"sell_average":5211,"signal":"big_distribution"},{"top":3,"buy_value":1984700000000,"sell_value":3907600000000,"imbalance_value":-1922900000000,"imbalance_bps":-2913,"buy_share_bps":3007,"sell_share_bps":5920,"buy_average":5212,"sell_average":5233,"signal":"big_distribution"},{"top":5,"buy_value":2939500000000,"sell_value":4540400000000,"imbalance_value":-1600900000000,"imbalance_bps":-2425,"buy_share_bps":4453,"sell_share_bps":6879,"buy_average":5211,"sell_average":5229,"signal":"big_distribution"},{"top":10,"buy_value":4477100000000,"sell_value":5551800000000,"imbalance_value":-1074700000000,"imbalance_bps":-1628,"buy_share_bps":6783,"sell_share_bps":8411,"buy_average":5213,"sell_average":5228,"signal":"big_distribution"}],"total_value":6600000000000,"average_price":5228,"foreign_net_value":-2300000000000,"foreign_net_bps":-3484,"both_sides":["AK","CC","MG","XL","YU","ZP"],"rounded":true}
 --- stderr
--- a/crates/idx-cli/tests/golden/stocks-bandar.json.golden
+++ b/crates/idx-cli/tests/golden/stocks-bandar.json.golden
@ -1,4 +1,4 @@
 exit: 0
 --- stdout
-[{"symbol":"BBCA.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":5,"signal":"big_distribution","imbalance_bps":-2426,"tiers":[{"top":1,"buy_value":841200000000,"sell_value":2200000000000,"imbalance_value":-1358800000000,"imbalance_bps":-2059,"buy_share_bps":1274,"sell_share_bps":3333,"buy_average":5191,"sell_average":5211,"signal":"big_distribution"},{"top":3,"buy_value":1984700000000,"sell_value":3907600000000,"imbalance_value":-1922900000000,"imbalance_bps":-2914,"buy_share_bps":3007,"sell_share_bps":5920,"buy_average":5212,"sell_average":5233,"signal":"big_distribution"},{"top":5,"buy_value":2939500000000,"sell_value":4540400000000,"imbalance_value":-1600900000000,"imbalance_bps":-2426,"buy_share_bps":4453,"sell_share_bps":6879,"buy_average":5211,"sell_average":5229,"signal":"big_distribution"},{"top":10,"buy_value":4477100000000,"sell_value":5551800000000,"imbalance_value":-1074700000000,"imbalance_bps":-1629,"buy_share_bps":6783,"sell_share_bps":8411,"buy_average":5213,"sell_average":5228,"signal":"big_distribution"}],"total_value":6600000000000,"average_price":5228,"foreign_net_value":-2300000000000,"foreign_net_bps":-3485,"both_sides":["AK","CC","MG","XL","YU","ZP"],"rounded":true}]
+[{"symbol":"BBCA.JK","from":"2026-10-16","to":"2026-10-16","investor":"all","board":"all","method":"top_concentration_v1","top":5,"signal":"big_distribution","imbalance_bps":-2425,"tiers":[{"top":1,"buy_value":841200000000,"sell_value":2200000000000,"imbalance_value":-1358800000000,"imbalance_bps":-2058,"buy_share_bps":1274,"sell_share_bps":3333,"buy_average":5191,"sell_average":5211,"signal":"big_distribution"},{"top":3,"buy_value":1984700000000,"sell_value":3907600000000,"imbalance_value":-1922900000000,"imbalance_bps":-2913,"buy_share_bps":3007,"sell_share_bps":5920,"buy_average":5212,"sell_average":5233,"signal":"big_distribution"},{"top":5,"buy_value":2939500000000,"sell_value":4540400000000,"imbalance_value":-1600900000000,"imbalance_bps":-2425,"buy_share_bps":4453,"sell_share_bps":6879,"buy_average":5211,"sell_average":5229,"signal":"big_distribution"},{"top":10,"buy_value":4477100000000,"sell_value":5551800000000,"imbalance_value":-1074700000000,"imbalance_bps":-1628,"buy_share_bps":6783,"sell_share_bps":8411,"buy_average":5213,"sell_average":5228,"signal":"big_distribution"}],"total_value":6600000000000,"average_price":5228,"foreign_net_value":-2300000000000,"foreign_net_bps":-3484,"both_sides":["AK","CC","MG","XL","YU","ZP"],"rounded":true}]
 --- stderr
--- a/crates/idx-cli/tests/golden/stocks-bandar.table.golden
+++ b/crates/idx-cli/tests/golden/stocks-bandar.table.golden
@ -1,7 +1,7 @@
 exit: 0
 --- stdout
 Bandar reading for BBCA.JK, 2026-10-16
-Signal (top 5): big distribution, -24.3% of value
+Signal (top 5): big distribution, -24.2% of value
 ┌─────┬────────┬──────┬───────┬────────┬─────────┬──────────┬──────────────────┐
 │ TOP ┆ BUY    ┆ SELL ┆ NET   ┆ NET %  ┆ BUY AVG ┆ SELL AVG ┆ SIGNAL           │
 ╞═════╪════════╪══════╪═══════╪════════╪═════════╪══════════╪══════════════════╡
@ -9,11 +9,11 @@ Signal (top 5): big distribution, -24.3% of value
 ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
 │ 3   ┆ 2.0T   ┆ 3.9T ┆ -1.9T ┆ -29.1% ┆ 5,212   ┆ 5,233    ┆ big distribution │
 ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
-│ 5   ┆ 2.9T   ┆ 4.5T ┆ -1.6T ┆ -24.3% ┆ 5,211   ┆ 5,229    ┆ big distribution │
+│ 5   ┆ 2.9T   ┆ 4.5T ┆ -1.6T ┆ -24.2% ┆ 5,211   ┆ 5,229    ┆ big distribution │
 ├╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌┼╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌┼╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┤
 │ 10  ┆ 4.5T   ┆ 5.6T ┆ -1.1T ┆ -16.3% ┆ 5,213   ┆ 5,228    ┆ big distribution │
 └─────┴────────┴──────┴───────┴────────┴─────────┴──────────┴──────────────────┘
-Total 6.6T IDR, average 5,228; foreign net -2.3T (-34.9% of value).
+Total 6.6T IDR, average 5,228; foreign net -2.3T (-34.8% of value).
 On both sides: AK, CC, MG, XL, YU, ZP; their gross figures overstate which way they traded.
 Method top_concentration_v1: the top 5 buyers' value minus the top 5 sellers' value, as a share of value traded; 5% or more reads accumulation, 15% or more big (negative: distribution). Brokers trade for many clients, so this is a heuristic, not advice.
 Note: the source rounds figures of a million and more to one decimal.
--- a/crates/idx-core/src/analysis/bandar.rs
+++ b/crates/idx-core/src/analysis/bandar.rs
@ -135,10 +135,12 @@ pub fn check_top(top: u8) -> Result<u8, IdxError> {
    }
 }

-/// `part` in basis points of `whole`; `None` without a positive whole.
+/// `part` in basis points of `whole`, truncated toward zero so a negative
+/// reading never reaches a threshold its magnitude has not; `None` without
+/// a positive whole.
 fn bps(part: i64, whole: Option<i64>) -> Option<i64> {
    let whole = whole.filter(|whole| *whole > 0)?;
-    i64::try_from((i128::from(part) * 10_000).div_euclid(i128::from(whole))).ok()
+    i64::try_from(i128::from(part) * 10_000 / i128::from(whole)).ok()
 }

 /// Sum of `field` over `flows`; `None` when any flow lacks it.
@ -326,6 +328,37 @@ mod tests {
        assert_eq!(report.method, METHOD);
    }

+    #[test]
+    fn test_bandar_tier_thresholds_are_symmetric_for_sign() {
+        let reading = |buy: i64, sell: i64| {
+            let s = summary(
+                vec![flow("AA", Some(buy), 100)],
+                vec![flow("BB", Some(sell), 100)],
+                2_100_000_000,
+            );
+            let tier = bandar_tier(&s, 1);
+            (tier.imbalance_bps, tier.signal)
+        };
+        // -4.9952% and -14.9952% stay short of the thresholds, like their
+        // mirror images.
+        assert_eq!(
+            reading(504_300_000, 609_200_000),
+            (Some(-499), Some(BandarSignal::Neutral))
+        );
+        assert_eq!(
+            reading(609_200_000, 504_300_000),
+            (Some(499), Some(BandarSignal::Neutral))
+        );
+        assert_eq!(
+            reading(504_300_000, 819_200_000),
+            (Some(-1499), Some(BandarSignal::Distribution))
+        );
+        assert_eq!(
+            reading(819_200_000, 504_300_000),
+            (Some(1499), Some(BandarSignal::Accumulation))
+        );
+    }
+
    #[test]
    fn test_analyze_bandar_never_counts_a_missing_figure_as_zero() {
        let s = summary(
--- a/crates/idx-core/src/analysis/mod.rs
+++ b/crates/idx-core/src/analysis/mod.rs
@ -31,6 +31,19 @@ pub struct Comparison {
    pub failures: Vec<(String, IdxError)>,
 }

+/// Readings weigh brokers against the value traded, which the source does
+/// not total for one investor side.
+fn check_investor(investor: BrokerInvestor) -> Result<(), IdxError> {
+    if investor == BrokerInvestor::All {
+        Ok(())
+    } else {
+        Err(IdxError::InvalidInput(format!(
+            "bandar needs --investor all: the broker summary has no total for {} investors alone",
+            investor.as_str()
+        )))
+    }
+}
+
 /// Bandar readings for several symbols, strongest accumulation first;
 /// symbols that failed are listed with their error.
 pub struct BandarScreen {
@ -57,6 +70,7 @@ impl Analysis<'_> {
        policy: CachePolicy,
    ) -> Result<Fetched<BandarReport>, IdxError> {
        let top = check_top(query.top)?;
+        check_investor(query.investor)?;
        let summary =
            self.idx
                .broker()
@ -73,6 +87,7 @@ impl Analysis<'_> {
        policy: CachePolicy,
    ) -> Result<BandarScreen, IdxError> {
        check_top(query.top)?;
+        check_investor(query.investor)?;
        let mut reports = Vec::new();
        let mut failures = Vec::new();
        for symbol in symbols {
--- a/crates/idx-mcp/src/server.rs
+++ b/crates/idx-mcp/src/server.rs
@ -205,7 +205,8 @@ traded (`imbalance_bps`), with a `signal` from big_accumulation (>= +1500) throu
 (within +-500) to big_distribution (<= -1500), headlined by `top` (default 5). Reports come \
 strongest accumulation first; tickers that fail are listed under `failures`. A heuristic over \
 end-of-day broker codes: brokers trade for many clients, and `both_sides` lists brokers whose \
-gross figures overstate their direction. `method` names the rules applied."
+gross figures overstate their direction. `method` names the rules applied. `investor` must be \
+`all`: the summary has no total for one investor side."
    )]
    async fn analyze_bandar(&self, params: Parameters<BandarParams>) -> ToolResult {
        let BandarParams {
--- a/crates/idx-mcp/tests/golden/tools.json
+++ b/crates/idx-mcp/tests/golden/tools.json
@ -1,6 +1,6 @@
 [
  {
-    "description": "Bandarmology for one or more IDX tickers from the broker summary: for the top 1, 3, 5 and 10 brokers per side, buy value minus sell value as basis points of value traded (`imbalance_bps`), with a `signal` from big_accumulation (>= +1500) through neutral (within +-500) to big_distribution (<= -1500), headlined by `top` (default 5). Reports come strongest accumulation first; tickers that fail are listed under `failures`. A heuristic over end-of-day broker codes: brokers trade for many clients, and `both_sides` lists brokers whose gross figures overstate their direction. `method` names the rules applied.",
+    "description": "Bandarmology for one or more IDX tickers from the broker summary: for the top 1, 3, 5 and 10 brokers per side, buy value minus sell value as basis points of value traded (`imbalance_bps`), with a `signal` from big_accumulation (>= +1500) through neutral (within +-500) to big_distribution (<= -1500), headlined by `top` (default 5). Reports come strongest accumulation first; tickers that fail are listed under `failures`. A heuristic over end-of-day broker codes: brokers trade for many clients, and `both_sides` lists brokers whose gross figures overstate their direction. `method` names the rules applied. `investor` must be `all`: the summary has no total for one investor side.",
    "inputSchema": {
      "$schema": "https://json-schema.org/draft/2020-12/schema",
      "properties": {
--- a/web/src/content/docs/cli/reference.md
+++ b/web/src/content/docs/cli/reference.md
@ -355,7 +355,7 @@ Examples:
 ### `idx stocks bandar`

 ```text
-Bandarmology from the broker summary: the top 1, 3, 5 and 10 buyers' value against the same number of sellers', as a share of value traded, with a signal from big accumulation to big distribution. Several symbols give a screen ranked by the headline tier (at most 100, one request each). A heuristic over end-of-day broker codes, not advice.
+Bandarmology from the broker summary: the top 1, 3, 5 and 10 buyers' value against the same number of sellers', as a share of value traded, with a signal from big accumulation to big distribution. Several symbols give a screen ranked by the headline tier (at most 100, one request each). Counts all investors (`--investor` must be `all`). A heuristic over end-of-day broker codes, not advice.

 Usage: idx stocks bandar [OPTIONS] <SYMBOLS>...

--- a/web/src/content/docs/cli/stocks.md
+++ b/web/src/content/docs/cli/stocks.md
@ -68,7 +68,8 @@ traded. The headline tier (`--top`, default 5) gives the signal:
 | -15% or less | big distribution |

 Several symbols give a screen ranked by that figure (at most 100, one request
-each), and it takes the same date and filter flags as `broker`. It is a
+each), and it takes the same date and board flags as `broker` (all investors
+only: the summary has no total for one side). It is a
 heuristic: a broker trades for many clients, and a broker on both sides of
 the summary is listed, since its gross figures overstate which way it traded.
 The JSON names the rules in `method` (`top_concentration_v1`).
--- a/web/src/content/docs/mcp/tools.md
+++ b/web/src/content/docs/mcp/tools.md
@ -12,7 +12,7 @@ message}` with `isError` set.

 ## `analyze_bandar`

-Bandarmology for one or more IDX tickers from the broker summary: for the top 1, 3, 5 and 10 brokers per side, buy value minus sell value as basis points of value traded (`imbalance_bps`), with a `signal` from big_accumulation (>= +1500) through neutral (within +-500) to big_distribution (<= -1500), headlined by `top` (default 5). Reports come strongest accumulation first; tickers that fail are listed under `failures`. A heuristic over end-of-day broker codes: brokers trade for many clients, and `both_sides` lists brokers whose gross figures overstate their direction. `method` names the rules applied.
+Bandarmology for one or more IDX tickers from the broker summary: for the top 1, 3, 5 and 10 brokers per side, buy value minus sell value as basis points of value traded (`imbalance_bps`), with a `signal` from big_accumulation (>= +1500) through neutral (within +-500) to big_distribution (<= -1500), headlined by `top` (default 5). Reports come strongest accumulation first; tickers that fail are listed under `failures`. A heuristic over end-of-day broker codes: brokers trade for many clients, and `both_sides` lists brokers whose gross figures overstate their direction. `method` names the rules applied. `investor` must be `all`: the summary has no total for one investor side.

 | Input | Type | Required | Description |
 | --- | --- | --- | --- |