Opening Cross

Ever see the start of a marathon? The starting gun goes off and then everyone is all clumped together at the starting line. The people in the front immediately start running, but if you're stuck in the back, you kind of have to mill around for a minute or two until everyone clears out.

The beginning of a Wall Street trading session is like that as well. Orders set to transact at the open all have to be filled, leading to a lot of activity in the opening stages of the day. On the NASDAQ stock market, this time period is known as the opening cross.

The term relates to the way the market matches orders in this busy part of the day and calculates opening prices. It's how NASDAQ tries to provide transparency and liquidity just before and in the moments surrounding the start of trading.

In marathon terms, it's like the ways race organizers prevent runners from tripping over each other or turning into a violent hair-pulling, foot-stomping mob.