Possible Alpaca Paper Trading Bug: SQQQ Filled at Wrong Prices

Alpaca Trading
1

Hi everyone,

I’m using Alpaca’s paper trading environment with an LLM trading agent, and I ran into something that looks like a serious pricing/execution inconsistency. I’d like to confirm whether this is a known issue or if anyone else has seen something similar.

Problem Summary

In my paper account, SQQQ orders are being filled at completely unrealistic prices. During the same trading session I observed:

Multiple fills at $15–$15.3

A large sell fill at $71+

However, the real market price for SQQQ during this period was consistently around $60–$70.
So there should be no scenario where a market buy gets filled at $15, especially not repeatedly, but paper trading processed all those low-price orders as filled.

image
image1613×579 92.4 KB

Questions

I just need to know whether:

  • this is a data feed bug,
  • a corporate action adjustment issue,
  • or something wrong in my setup.

Thanks in advance for any insights.

2

@BryantSuen The short answer is that your orders filled correctly. SQQQ had a 1:5 reverse stock split effective 2025-11-20 ET which made any adjusted prices before that date appear five times the actual price. When you stated “the real market price for SQQQ during this period was consistently around $60–$70” you were probably looking at adjusted prices and not “real” or raw prices.

It appears the screenshot you posted shows times in UTC+8:00. If the times are adjusted for US Eastern Time (ie US market time) then the first order filled on 2025-11-20 while the others filled before the split which accounts for the difference in fill prices.

I can go into more detail if needed, but this may clear up the confusion.