QQQ, BKNG, ADP, GILD: ETF Outflow Alert

Symbols mentioned in this story: QQQ, BKNG, ADP, GILD Exchange traded funds (ETFs) trade just like stocks, but instead of ''shares'' investors are actually buying and selling ''units''. These ''units'' can be traded back and forth just like stocks, but can also be created or destroyed to accommodate investor demand..