Are you sure that's what aggregate limit means? $150M is miniscule for IB, which has billions in customer equity. Even the policy at TOS has a $200M limit and TOS is about 1/10 the size. I always assumed it meant that was the total of all your accounts that Llyods will insure (you can have accounts at other brokers that are insured through Lloyds).
If $150M is for all of IB, that would be like someone insuring their $350k house for $25k.
That sure makes it sound like $150M is the limit for all of IB. I guess they are expecting SIPC to cover the vast majority of their customers. The $150m limit suggests that they don't have many customers with over $1m (or that perhaps the $150M is inadequate to protect their entire customer base). TOS would appear to have more accounts in excess of $1m based on their higher coverage.
