The high-frequency trading (HFT) firms utilized minimal orders on the BATS exchange, typically the smallest size of 100 shares. These orders were not aimed at genuine trading; rather, they served as a strategic tool to extract information from unsuspecting investors about market preferences and intentions. By placing these negligible orders, HFT firms could gain insights into buying and selling trends without actually committing capital to real transactions.

BATS, the marketplace for these activities, was established by HFT firms themselves, reflecting their vested interest in maintaining control over market dynamics. The use of such tactics illustrates how the trading landscape can be manipulated by sophisticated players who prioritize information acquisition over traditional buying and selling. This practice has significant implications for the integrity of market activities and the experiences of regular investors.