By act I mean act upon having knowledge of your trade and place a trade before your trade. Read the article to see what was happening to trades.
Ray, have you ever traded a stock?
The only way high speed traders can affect the price you pay is if you use a “Market” order.
I have no idea why anyone would ever use a “Market” order.
If you use a “Limit” order, your order MUST be filled at the exact terms you specify, or it cannot be filled at all.