Why my limit order doesn’t fill?

I will look for MarketWatch.
Thank you for your answer, I really appreciate you taking time to reply!

Ah ok, I could definitely see why this would hapopen. a $3-5 limit on a stock like Tesla, that can change very quickly.

If you're using your brokerage, it's critical to understand that the brokerage has a 15 minute delay, unless you subscribe to an advanced data package. This will be the case with most every broker.

So, if you're using Questrade for example and it says Tesla is trading at $1500, this is what it was trading at 15 minutes ago. The price could be $1450, it could be $1550, it could be anything.

So, say the price was $1500 and you put a limit of $1505 in. If the stock is trading at $1520 on a real time basis, it will give you the illusion through your brokerage (15 minute delay) that the order SHOULD be filled. But it's not.

However, there may be situations where the stock is actually lower than what your brokerage says. So you could put a limit order of $1500 in, and it could be filled at like $1490.

I believe one site that does provide live data is MarketWatch.

I really hope this makes sense. I know I rambled on a bit haha.

I was buying three shares of Tesla stock for $1,575/share (that was 5 days ago). I placed my order at the moment when the asking price was $1,571-1,572 (my order was good for the day and then it got canceled at 4pm, by then the price per share was at least $100 more than during pre-market hours when I placed my order)
As a new investor, I never knew that this kind of situation could be possible, I was so sure that my order was filled instantly, that I did not even bother to check on it, only later that day I discovered that my order was still hanging there, but it was too late for that price.

It's possible there isn't enough liquidity to fill an order, but if you're placing the limit $3 to $5 higher, chances are you aren't buying some penny stock with low liquidity.

If you don't mind, what was the stock, and how many shares?

And also, just to confirm you have the order right, I will use an example. Say the stock was $5. You've put a buy limit order in for $8, and made it GTC (good 'till canceled)?