diff --git a/main.py b/main.py
index 7f947a2..a94b74f 100644
--- a/main.py
+++ b/main.py
@@ -8,6 +8,25 @@ logging.basicConfig(
 logger = logging.getLogger(__name__)
 
 
+def _run_signals(label: str = ""):
+    from db.db import get_all_buys_for_reprocess
+    from signals.filter_engine import process_filing
+
+    filings = get_all_buys_for_reprocess()
+    count = 0
+    seen: set[tuple] = set()
+    for filing in filings:
+        as_of = (filing.get("transaction_date") or filing.get("filed_date") or "")[:10]
+        key = (filing["ticker"], as_of)
+        if key in seen:
+            continue
+        seen.add(key)
+        if process_filing(filing, as_of_date=as_of) is not None:
+            count += 1
+    logger.info(f"Signal generation{' ' + label if label else ''}: {count} signals")
+    return count
+
+
 def _process_filing(filing: dict):
     from signals.filter_engine import process_filing
     from alerts.slack_alert import send_slack_alert
@@ -17,9 +36,7 @@ def _process_filing(filing: dict):
     if signal is None:
         return
 
-    logger.info(
-        f"Signal: {signal['ticker']} score={signal['score']} cluster={signal['cluster_size']}"
-    )
+    logger.info(f"Signal: {signal['ticker']} score={signal['score']} cluster={signal['cluster_size']}")
 
     if config.SLACK_WEBHOOK_URL:
         send_slack_alert(signal)
@@ -37,6 +54,7 @@ def _close_expired_positions():
 
 
 def cmd_run():
+    """Continuous live polling — polls EDGAR every 10 min, processes signals, executes trades."""
     from db.db import init_db
     from ingestion.edgar_poller import run_poller
 
@@ -50,7 +68,44 @@ def cmd_run():
     run_poller(on_new_filing=on_new_filing)
 
 
+def cmd_backfill():
+    """Bulk-ingest historical Form 4 filings from SEC EDGAR quarterly archives.
+
+    Usage:
+      python main.py backfill --years 2023 2024        # full year range
+      python main.py backfill --year 2024 --quarter 1  # single quarter
+    """
+    import argparse
+    from db.db import init_db
+    from ingestion.sec_bulk_ingest import ingest_years, ingest_quarter
+
+    parser = argparse.ArgumentParser(prog="main.py backfill")
+    group = parser.add_mutually_exclusive_group(required=True)
+    group.add_argument("--years", nargs=2, type=int, metavar=("FROM", "TO"),
+                       help="Inclusive year range, e.g. --years 2023 2024")
+    group.add_argument("--year", type=int, help="Single year (use with --quarter)")
+    parser.add_argument("--quarter", type=int, choices=[1, 2, 3, 4])
+    parser.add_argument("--no-signals", action="store_true",
+                        help="Skip signal generation after ingest")
+    args = parser.parse_args(sys.argv[2:])
+
+    init_db()
+
+    if args.years:
+        stored = ingest_years(args.years[0], args.years[1])
+    else:
+        if not args.quarter:
+            parser.error("--year requires --quarter")
+        stored = ingest_quarter(args.year, args.quarter)
+
+    logger.info(f"Ingest complete: {stored} transaction rows stored")
+
+    if not args.no_signals:
+        _run_signals("after backfill")
+
+
 def cmd_backtest():
+    """Backtest signals in the DB against historical prices via yfinance."""
     from backtest.backtest import run_backtest, print_summary
     import config
 
@@ -64,22 +119,24 @@ def cmd_backtest():
     print_summary(summary)
 
 
-def cmd_fetch_once():
-    from db.db import init_db
-    from ingestion.edgar_poller import fetch_and_store_new_filings
+def cmd_simulate():
+    """Portfolio simulation with configurable strategy and transaction cost params.
 
-    init_db()
-    filings = fetch_and_store_new_filings()
-    logger.info(f"Fetched and stored {len(filings)} new filings")
-
-    for filing in filings:
-        _process_filing(filing)
+    Usage:
+      python main.py simulate [--holding-days 7] [--buy-delay 1]
+                              [--position-size 0.10] [--min-score 0] [--min-cluster 1]
+                              [--capital 100000]
+                              [--spread 0.003] [--slippage 0.002] [--commission 0.001]
+    """
+    from backtest.simulate import main as sim_main
+    sim_main()
 
 
 COMMANDS = {
     "run": cmd_run,
+    "backfill": cmd_backfill,
     "backtest": cmd_backtest,
-    "fetch-once": cmd_fetch_once,
+    "simulate": cmd_simulate,
 }
 
 if __name__ == "__main__":