Why an order was triggered even if there wasn't a high price showing on the daily candle

[Lvran Hao]

Today, I got a strange problem. I had a buy-stop order. It shouldn't be triggered as a trade because the daily high did not hit the buy price. How come it was triggered. I have a feeling that the broker server may have fluctuate or spike to to trigger the order to a trade, but not showing on the graph. I raised this to my brokerage, but they asked me to fill in a form (kind of dispute, still waiting). Is this normal? If this happens, then it has huge impact to the algorithms if we try to automate the trading. thanks

[Fernando Carreiro]

Lvran Hao:
Today, I got a strange problem. I had a buy-stop order. It shouldn't be triggered as a trade because the daily high did not hit the buy price. How come it was triggered. I have a feeling that the broker server may have fluctuate or spike to to trigger the order to a trade, but not showing on the graph. I raised this to my brokerage, but they asked me to fill in a form (kind of dispute, still waiting). Is this normal? If this happens, then it has huge impact to the algorithms if we try to automate the trading. thanks

Buy orders open (or are triggered) at the Ask price (not the bid price). Charts are shown with bid prices (sometimes with last prices depending on type of symbol).

In other words, due to spread, then it can trigger an order even if chart does not show that.

Is this normal? Yes, it is quite normal and very frequent.

So pay attention and learn the following:

• Buy orders open at Ask price and close (S/L, T/P, etc.) at Bid price.
• Sell orders open at Bid price and close (S/L, T/P, etc.) at Ask price.
  

[Lvran Hao]

Fernando Carreiro #:

Buy orders open (or are triggered) at the Ask price (not the bid price). Charts are shown with bid prices (sometimes with last prices depending on type of symbol).

In other words, due to spread, then it can trigger an order even if chart does not show that.

Is this normal? Yes, it is quite normal and very frequent.

So pay attention and learn the following:

• Buy orders open at Ask price and close (S/L, T/P, etc.) at Bid price.
• Sell orders open at Bid price and close (S/L, T/P, etc.) at Ask price.
  

Thanks Fernando.

I do understand the concept of bid and ask price. I didn't know all chart is actually showing Bid price. Thanks for confirming this. that explains why. I suspected it, but cannot be for sure. 

you are legend. thanks