Oil Service Holdrs Trust Sample Contracts

Oil Service Holdrs Trust – OIL SERVICE HOLDRS TRUST AMENDMENT NO. 1 TO THE DEPOSITARY TRUST AGREEMENT (August 15th, 2011)

AMENDMENT NO. 1 TO THE DEPOSITARY TRUST AGREEMENT (this “Amendment”), dated as of August 11, 2011, between Merrill Lynch, Pierce, Fenner & Smith Incorporated, as initial depositor (the “Initial Depositor”), and The Bank of New York Mellon (formerly known as The Bank of New York), as trustee (the “Trustee”), all Depositors and all Owners and Beneficial Owners from time to time of Depositary Trust Receipts issued under the Depositary Trust Agreement referred to below.

Oil Service Holdrs Trust – 1,000,000,000 Depositary Receipts Oil Service HOLDRS (SM) Trust (August 15th, 2011)

This prospectus supplement revises as specified the information contained in the prospectus dated March 15, 2011 relating to the sale of up to 1,000,000,000 depositary receipts by the Oil Service HOLDRS Trust. Investors should read the prospectus dated March 15, 2011 as revised by this prospectus supplement. Except as specifically stated herein, the information in the prospectus dated March 15, 2011 is unchanged.

Oil Service Holdrs Trust – VAN ECK® GLOBAL AND MERRILL LYNCH ENTER AGREEMENT REGARDING OIL SERVICES HOLDRS TRUST (OIH) AND FIVE OTHER HOLDRS® Investors in Six HOLDRS to be Asked to Exchange into Market Vectors® ETFs (August 15th, 2011)

NEW YORK, (August 12, 2011) – Van Eck Global and Merrill Lynch & Co., a subsidiary of Bank of America Corporation ("Merrill Lynch"), have entered into an agreement relating to Merrill Lynch-sponsored HOLding Depository ReceiptS (“HOLDRS”). Van Eck’s Market Vectors ETF Trust plans to offer investors in six HOLDRS -- Oil Services (OIH), Semiconductor (SMH), Pharmaceutical (PPH), Biotech (BBH), Retail (RTH), and Regional Bank (RKH) -- the opportunity to exchange their shares in these funds for shares of new Market Vectors exchange-traded funds (ETFs). These HOLDRS had approximately $3.65 billion in aggregate assets and a combined 30-day average daily trading volume of approximately 20.07 million shares as of the close of trading on August 11, 2011. Terms of the transaction were not disclosed.

Oil Service Holdrs Trust – 1,000,000,000 Depositary Receipts Oil Service HOLDRS (SM) Trust (November 14th, 2007)

This prospectus supplement supplements information contained in the prospectus dated August 15, 2007 relating to the sale of up to 1,000,000,000 depositary receipts by the Oil Service HOLDRS (SM) Trust.