Quantitative suitability (Supplementary Material .05(c)) requires grounds for believing that a run of recommended trades, each defensible on its own, is not excessive or unsuitable when viewed as a whole against the customer's profile. There is no single yardstick for excessive trading, but the turnover rate, the cost-to-equity ratio and in-and-out trading are named indicators. Firms monitor accounts with activity thresholds, send active-account letters and document the review. Since the 2020 amendment the control-of-account element was removed for the Regulation Best Interest population; for accounts still under Rule 2111 the firm's surveillance should cover both.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.