Incorrect spikes/peaks in historical data

Alpaca Market Data
#1

I use the (paid) SIP feed for historical 1 min OHLC data. The data seems pretty much in line with most sources except from time to time there are these random incorrect spikes (see image, top is Alpaca data, bottom is Yahoo).

graph
graph1169×1092 129 KB

What’s going on there and is there a fix? This makes the data pretty useless for backtesting because these spikes will almost certainly (incorrectly) trigger stop-loss or take-profits limits.

1 Like
#2

I’ve seen this with historical data before as well. I also see it a lot when streaming live trade data, where wild prices will come through, but when compared to Yahoo, Fidelity, or even Alpaca’s own data after the current minute bar is finalized, those prices “never happened”.