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Live (paper) trading

Live mode warms up the strategy with recent history, subscribes to the Alpaca real-time bar stream, and routes signals to the broker as bracket orders.

make live
# or
uv run python main.py live --strategy volume_spike --scanner volume --symbols NVDA,META,TSLA
warning

With PAPER_TRADE = True (the default) this trades the paper account. Set it to False only when you intend to trade real money.

What happens on start​

  1. The scanner picks the universe from your candidate symbols.
  2. The engine fetches enough history to make every indicator valid, and seeds the strategy's rolling buffers (warm-up).
  3. It subscribes to the live bar stream for every monitored symbol. The stream auto-reconnects with backoff if the socket drops.
  4. Each streamed OHLCV bar updates the strategy, which emits a signal.
  5. Actionable signals go to the LiveTrader, which sizes the position and submits a bracket order (entry + stop-loss + take-profit) through the broker.
  6. In parallel, the trade-update stream logs fills/cancels/rejects so you can see what the account is actually doing.

Press Ctrl-C to stop.

Order safety​

  • Entries are skipped while an order is pending for that symbol, so a repeated signal can't double-submit before the first fills.
  • A discretionary close cancels the resting bracket legs first, so you're never left with an orphaned stop/take order.
  • Orders are only sent during market hours (the clock is checked, with a short cache; disable with respect_market_hours=False if you need extended-hours).

Position sizing​

By default each entry is sized by the strategy's risk-per-trade / stop-loss config (RiskBasedSizer). Add --portfolio to instead size positions by portfolio weights computed with the OR-Tools allocator — capital is shared across the universe rather than sized per trade:

make live-portfolio
# or
uv run python main.py live --scanner volume --symbols NVDA,META,TSLA \
    --portfolio --max-positions 5 --max-weight 0.25

With --portfolio, only the symbols the allocator funds are traded; if OR-Tools isn't installed or nothing is funded, it falls back to risk-based sizing. See Portfolio allocation.

Or use --beta-sizing to scale each position inversely by its beta vs a benchmark (default SPY) — higher-beta names get smaller positions, evening out risk:

make live-beta
# or
uv run python main.py live --scanner volume --symbols NVDA,META,TSLA --beta-sizing --benchmark SPY

Managing the account​

make cancel-orders      # cancel all open orders
make close-positions    # liquidate all positions (also cancels orders)

The full real-time path is described in The Engine and Broker Abstraction.