We wanted to provide you with an updated copy of the agreements and disclosures associated with your account ending in xxxx-xxxx with optionsXpress. While we are not making any changes to the fees or commissions associated with your Account, the changes we are making are significant, and we encourage you to read and retain them, as they contain important terms and conditions that apply to your Account. Your continued use of your Account will signify your acceptance of these revised terms.

As part of these changes, we are modifying the Bank Sweep Feature (formerly the Bank Insured Deposit Program). On or after December 3, 2012 (Effective Date), your funds on deposit will be withdrawn from the banks currently participating in the Bank Insured Deposit Program (Program Banks), and the Program Banks will no longer be available to accept your funds. Your funds will be held overnight at optionsXpress and the following day will be automatically deposited, or swept, without limit into deposit accounts at Charles Schwab Bank, a Federal Deposit Insurance Corporation (FDIC)-insured depository institution affiliated with optionsXpress (Schwab Bank).

As a result of this change, the aggregate maximum potential FDIC insurance coverage for your deposits will be reduced from $2.5 million per individual and $5 million per joint account of two persons, to $250,000 per individual and $500,000 per joint account of two persons, subject to FDIC rules on aggregation of deposits. Additional information about these changes is provided in the attached Notice and the accompanying Cash Features Disclosure Statement (PDF).

Or did they sell it to Ameritrade ToS?

I sweep funds over the minimum I need to trade all the time. Hate to admit it but I don't trust any of them.