Bet against the all-time greats at your own risk. 

"Don't short all-time greats when the talent is still there," says Baird tech analyst Colin Sebastian, grouping Facebook's (FB) - Get Report stock and NFL great Aaron Rodgers together. 

Sebastian makes a good point on both well-known names. 

On Facebook

From the Cambridge Analytica debacle to a surprisingly ugly second quarter (vs. Wall Street estimates), Facebook has had a terrible 2018. Shares of the social media beast are down 4% on the year while the Nasdaq Composite I:IXIC has gained 14%. 

Even still, Sebastian says it's hard to bet against a company with more than a billion users. 

Points out Sebastian:

"Facebook has been one of the most successful Internet companies in history, with almost 1.5 billion people using its core product every day. Concerns around waning engagement and Stories monetization dampened enthusiasm for the company's near-term growth/profitability outlook, but we remain constructive on shares given best-in-class targeting capabilities and unmatched scale."

On Aaron Rodgers

The Green Bay Packers star quarterback is fresh off inking a four-year, $134 million contract extension. That's mega deal comes despite Rodgers showing his age the past two years with assorted injuries cutting into playing time.

Similar to Facebook though, Sebastian thinks betting against a Rodgers revival is foolish. 

The stats simply say do the opposite this fantasy football season. Says Sebastian:

"Aaron Rodgers is, at least statistically, the greatest QB to ever play the game (sorry Pats fans), but missed half of 2017 with a broken collarbone, and there are some concerns regarding a general lack of surrounding offensive talent. Rodgers has thrown for at least 30 touchdowns every year he's played at least 15 games since 2011, and his rushing ability remains underrated (averaged 350 yards/year in 2015 and 2016). Fresh off signing the largest contract in NFL history earlier this week, we believe rumors of Rodgers' demise have been greatly exaggerated."

Here's what Jim Cramer is saying about Facebook right now