With stock prices in correction zone, the world's largest companies may be poised to unleash their mega firepower to close on some big deals.

Aggregate M&A "firepower" -- the sum of a company's readily available cash and debt capacity within its credit rating -- is currently estimated at a mind-blowing $5 to $5.5 trillion for the S&P 500, says strategists at Citi. The total is up markedly from the $3.3 trillion seen at the start of 2017. 

"Not all of this increase is due to multinational companies gaining unrestricted access to their foreign cash holdings, domestically focused companies will also see an increase in their debt capacity due to larger after-tax cash flows available to delever following an acquisition," Citi explains. "While share repurchases will likely increase in 2018, we believe that M&A across all sectors will also be impacted."

M&A is already off to a strong start in 2018 despite the return of market volatility. Global year to date announced deal volume is $449 billion, up 21% from the prior year. Nearly half of the volume is from mega-deals (larger than $5 billion). Technology (over $60 billion) and healthcare (over $45 billion) are the most active sectors. 

Two of the most headline-grabbing deals so far this year include Keurig's $18.7 billion purchase of Dr. Pepper Snapple (DPS) and Celgene's (CELG) - Get Report  $9 billion bid for Juno Therapeutics  (JUNO) .

Deals announced in 2018 have also been well-received, notes Citi. An average one-day excess return of 3.6% has been rewarded to the acquirer upon announcement.

The million dollar question is whether what started as another solid year for M&A will dry up thanks to the stock market correction. So far, the answer isn't readily apparent. 

"The sudden increase in volatility over the past 10 days has resulted in a slowdown in announced M&A volume, and continued volatility could dampen M&A activity," Citi says. "While periods of high equity market volatility create uncertainty, they also provide opportunities for financially strong buyers." 

TheStreet is always talking big deals on Morning Jolt. Check out the archives below.