Buying stocks and bonds is spending the money. You've given the money to somebody else in exchange for something. Now they have the same choice as you did - spe

Buying stocks and bonds is spending the money. You've given the money to somebody else in exchange for something. Now they have the same choice as you did - spend or save. If you save it in a tax free savings account even better. The bank holding the offsetting reserves then does the buying via the DMO cash management process.