SPDR S&P 500 (SPY)

[DowDeva]

That 'they filled my trade too quickly' thing sometimes is true, sometimes isn't, I have found. I think when it isn't true, it's because there is just a ton of liquidity out there. Like the SPY, for instance, orders flying around all over the place.

However, yesterday 'they' filled my NVDA order to buy way too quickly, as you said. It had never happened before to me, so I got out quickly and went short and it tanked. NVDA is pricey and they usually keep me waiting, so it was a sign to me.

But it doesn't always work that way and I could have been wrong.