Generac Holdings Inc (NYSE:GNRC) is scaling the New York Stock Exchange (NYSE) today, last seen up 27.3% to trade at $223.23. The company secured an $2.4 billion deal with Amazon.com (AMZN) to supply backup power generators for its data centers. Amazon was also granted the right to purchase $320 million worth of Generac stock.

Generac stock is pacing for its best single-session gain on record. Yesterday, GNRC traded at its lowest level since Feb. 6, with a Relative Strength Index of 28. Now, the shares are back above their year-over-year breakeven level and boast a 63.4% year-to-date lead.

Shorts could be in trouble. Short interest increased by nearly 30% in the most recent reporting period, and the 2.66 million shares sold short account for 4.5% of the stock's total available float.

What's more, Generac has tended to outperform volatility expectations over the past year. This is per its Schaeffer's Volatility Scorecard (SVS) of 89 out of 100.