Wall Street is pinning its bets of an economic rebound this year on mass vaccinations and a virus brought under control, but new coronavirus strains threaten that sunny outlook, a number of firms are warning.

Why it matters: None downgraded growth forecasts because of the variants, but they’re acknowledging there’s a new asterisk to the anticipated economic recovery.

Shares in GameStop surged as high as $76.73 on Friday in what has been described as an "epic short squeeze."

Why it matters: The GameStop fight, with Redditors and TikTok influencers on the long side and investment professionals like Citron Research's Andrew Left on the short side, has turned ugly in recent days. But for the time being, the amateur investors are winning.

Fears of an asset bubble are gaining ground among investors, Bank of America surveys out this week show.

Why it matters: The coronavirus is still the top fear, followed by rising interest rates. But there was the biggest jump among investors that mentioned "asset bubble" as a concern.

The pandemic helped to pull big banks’ bond trading revenue out of a multi-year slump.

Why it matters: Revenue within the so-called fixed income, currency and commodity (FICC) divisions has been slowing for years.

America’s big banks capped off a winning year, led by soaring Wall Street-facing business lines.

Why it matters: Banks cashed in on the white-hot IPO market, record debt issuance, and sky-high trading volume — all of which played out as economic peril softened the consumer side of their businesses.

One of the most high-risk, high-return trading strategies of the moment is also the most democratic: Buying the stocks being pumped up on Reddit and TikTok, and then selling them for a huge short-term profit.

The intrigue: While most active trading strategies require expensive professional-grade software, this is a strategy that’s accessible to anybody who's Extremely Online.

50% of Americans changed their investing strategy after seeing the result of the presidential election, according to a Harris Poll survey for Empower Retirement and Personal Capital shared exclusively with Axios.

Why it matters: The election and the intense news cycles following it were perceived, correctly, as an inflection point of historical proportions. Doing nothing is hard in such situations, even if sticking to your long-term plan is what most financial advisers would recommend.

Plug Power's share price fell 6% on Thursday and slipped another 1% in after-hours trading following a Hindenburg Research-esque short seller report on the company from Kerrisdale Capital.

What they're saying: "We are short shares of Plug Power, a $40 billion provider of hydrogen fuel-cell solutions that’s set to generate a paltry $300 million in revenue in 2020 and trades at 40x its own aggressive revenue projection for 2024."

U.S. stock markets hit record highs during President Trump's time in office, but mostly underperformed his predecessor.

By the numbers: The stock market selloff that followed the outbreak of the coronavirus pandemic wiped out three and a half years' worth of market gains for Trump. As of March 23, 2020, the S&P 500 had lost 1.5% since Trump's first day in office.

Economic recovery will not be linear as the world continues to grapple with the uncertainty of the pandemic.

Why it matters: Despite being propped up by an extraordinary amount of fiscal stimulus and support from central banks, the state of the global economy remains fragile.