Quantity ordered is less than requested

I am new to Alpaca so apologies if this is something trivial or already known.

I am trying out an algo via signalstack on paper trading and I find that if I order 1 quantity of ETH, the order goes through, but it actually fills 0.9975 instead of 1. Any ideas as to why it is not exactly 1?


as the order is filled at the price you requested it at {is sent} then the “filled qty” is sent back to you if the price is above the share price when requested, “no buyers” the remaining parts of the order is rejected

@arnav_8 What @kris mentioned can happen and that is what is called a partial_fill. The order will remain open and try to fill the remaining portion. This can happen with either market or limit orders. Market orders will typically fill completely within a few minutes, however limit orders may not fill for a while (or ever) if the price remains outside one’s limit price. It’s a good practice when using limit orders to check if it hasn’t filled and either cancel the order or probably better, replace the limit price to a value which will fill.

However, that is not what happened in the case of buying 1 ETH but ending up with .9975 ETH. This is because crypto fees are withdrawn from the ‘final’ currency. The base crypto fee is .25% which is the difference between .9975 and 1.0. If one uses USD to buy ETH (ie USD/ETH) the transaction fee reduces ETH. If one sells ETH to get USD (ie ETH/USD) then the fee reduces the cash or USD in the account. There is more on how fees are handled in the docs here.

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Makes sense. Thank you @Dan_Whitnable_Alpaca and @kris !
I’ll adjust the algo accordingly.
Thanks again!

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