# Alpaca web socket trade stream have 20 percent less trades than Polygon Trade stream

**URL:** <https://forum.alpaca.markets/t/alpaca-web-socket-trade-stream-have-20-percent-less-trades-than-polygon-trade-stream/4914>\
**Category:** Alpaca Market Data\
**Created:** [March 12, 2021, 12:52am UTC](https://forum.alpaca.markets/t/alpaca-web-socket-trade-stream-have-20-percent-less-trades-than-polygon-trade-stream/4914 "2021-03-12T00:52:14Z")\
**Posts on this page:** 1\
**Showing post:** 8

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**Author:** ![Abh](https://avatars.discourse-cdn.com/v4/letter/a/c68b51/32.png) [@Abh](https://forum.alpaca.markets/u/Abh)\
**Post date:** [March 13, 2021, 8:23am UTC](https://forum.alpaca.markets/t/alpaca-web-socket-trade-stream-have-20-percent-less-trades-than-polygon-trade-stream/4914/8 "2021-03-13T08:23:25Z")

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Also I noticed another difference: trades reported via Alpaca which has condition “F” (Intermarket Sweep) doesn’t have any condition like “Trade Thru Exempt” with them.

> > “{\n "T": "t",\n "i": 56056,\n "S": "AAPL",\n "x": "P",\n "p": 120.22,\n "s": 100,\n "t": "2021-03-10T17:08:21.151366144Z",\n "c": [\n "@",\n "F"\n],\n "z": "C"\n}”

But in poly feed and historic data most of condition 14 (Intermarket Sweep) trades also have condition 41(Trade Thru Exempt) attached to them.  
For trading decision purpose I generally ignore trades with condition 41 because they doesn’t reflect true price. But on Alpaca side this is missing.

The same trade look like this on Poly side

> > price: 120.22  
> > size: 100  
> > trade\_id: “56056”  
> > exchange\_id: 11  
> > tape: 3  
> > sip\_timestamp {  
> > seconds: 1615396101  
> > nanos: 151729411  
> > }  
> > exchange\_timestamp {  
> > seconds: 1615396101  
> > nanos: 151366144  
> > }  
> > sequence\_no: 3742968  
> > condition: 14  
> > condition: 41

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