Shake Shack Gains Nearly 10% Thanks To Late-afternoon Jump

Shares in Shake Shack Inc. climbed 9.9% Wednesday, scoring their biggest daily gain since their strong debut in late January. Much of the move came in the last half-hour of trading. Market watchers on Twitter discussed possible drivers for the move, but weren't settling on a single reason for it. The New York burger chain's shares finished on Wednesday at $42.92, roughly double their IPO price of $21, but below an intraday record above $52 hit on the first day of trading.