Massive paper trading latency vs. live trading

I am interested in higher-frequency trading, so I am measuring the latency of Alpaca order executions. There is a huge difference between the paper trading latency and the live trading latency!

At ~2:15 PM ET today, I submitted 2 pairs of buy/sell market day orders for 25 shares of AAPL, one using paper trading and one using live trading.

  • Live trading: 14 ms for both the buy and the sell order
  • Paper trading: 731 ms for the buy order and 107 ms for the sell order

I would have expected paper trading to be faster than live trading, not to be an order of magnitude slower…

Take a look at quote timeliness as well with live account. Snapshot date/time versus quote’s embedded date/time. I found the Alpaca data to be very out of time (RESTFUL). Unusable for intraday trading. Have not tried websocket because it is limited to 30 tickers. Evaluating IEX data now. $200/month but I can get timely intraday data, and entire market superset in one API call. It would be interesting to see what you find re timeliness.