This seems somewhat ironic to me. If what everyone assumes (that he's used many tax shelters and loop holes to avoid paying significant taxes) is true, it would be pretty hypocritical.
Gee, I wonder if this tweet is in any way connected to his previous one about weakening the USD to match the (alleged) currency manipulations of the Euro and China?<p>Please hang on to those US dollars. They are very solid, strong and stable. If the S&P 500 hits all time highs, its certainly because everyone is getting so rich, and not because we are inflating the currency. ;-P