Help understanding once per bar vs tick

[cmuphyfx]

Hi there,

Relatively new to EAs, but I have a background in software so I'm picking it up pretty quickly. I do have a fundamental question on why an EA that was built for a higher timeframe, like M5 or M15 operates differently on once per bar vs once per tick data? The signals I'm using are on the closing candles of M5 or M1, so it seems to me that what happens during that candle is irrevelent to my strategy - but, the backtester thinks differently as my strategy is not nearly as successful on tick data as it is on OHLC. Can someone explain it to me? I did search and dug through old posts but I didn't find a super clear explanation.

Additionally, for bonus points... Is there anything I can do to optimize my EA such that it performs like it does in an OHLC backtest on the tick data? I'd be retired next month if the performance matched!

Thanks!

[jstap]

A tick can happen multiple times a second, O=open, H=high, L=low, C=close, OHLC could happen only a few times in an hour.

[cmuphyfx]

1M OHLC is just the Open of the candle, high of the candle, low of the candle, close of the candle for each 1M candle, as I understand it... So there are only 4 values to process - still don't understand how tick data could affect my algo if I'm trading on the 5M, 15M etc...

[jstap]

You may be wrong as in only 1m candle, either way you see why they are not the same, and why every tick is better for testing.