But, as he points out, velocity can slow because of positive events, such as consumers and businesses shifting money from bonds and other illiquid investments to cash so they can spend it.

FORBES: Spend That Cash

With so little IPO activity, Chinese banks are shifting their focus to bonds or trading.

WSJ: China Banks Change Tack as Hong Kong IPOs Dry Up

What to watch out for: housing and retail sales further strengthening, and investors shifting even more of their holdings from bonds to stocks.

WSJ: Stocks Testing Records��But There's Still Room to Run