Do you think pro traders and funds use martingale/grid?

[Osama Shaban]

I believe they use High Frequency Trading algorithms.

Their big capital enables them to get more deeper prices with faster price feed and execution, this in return will highly improve their trading performance. 

[Michalis Phylactou]

Cause the majority of EAs being sold that appear to be in profit (for some period)  employ this , wondering if in reality the pros do that.

Or just HFT or trades with 200-400 pips TP that are left opened for days