Interactive Brokers (IBKR) September DARTs 4.11mn, -4% M/M

IBKR's monthly DARTs release is one of the few near-real-time reads on US retail and active-trader engagement, and the stock has historically traded on the sequence of these prints between quarterly earnings, with sequential direction mattering more than the level. A modest single-digit month-on-month decline sits well within the normal seasonal and volatility-driven range for this series; what has moved the name in past episodes is a break in the trend across consecutive months or a divergence from the peer set, since the listed discount brokers and exchanges report comparable activity metrics on similar schedules and the relative print is the cleaner signal. The distinction worth drawing is between activity softness driven by lower market volatility, which compresses commission revenue but tends to leave net interest income intact, and genuine account attrition, which is the rarer and more damaging read. Client equity and margin loan balances, usually disclosed alongside or shortly after, are the follow-ons that determine whether the revenue mix shifts toward or away from the interest-rate-sensitive leg. As a single monthly data point, the signal is directional rather than conclusive.