What happened

Shares of entertainment giant Walt Disney (DIS 0.28%) gained 22.1% in November 2020, according to data from S&P Global Market Intelligence. The House of Mouse generally followed the soaring market higher, apart from an outsized gain when investors caught wind of effective COVID-19 vaccines.

So what

Disney shares rose 11% in a single day on Nov. 9. The big news that day came from pharmaceutical companies Pfizer (PFE 1.29%) and BioNTech (BNTX 1.77%), who revealed that their vaccine candidate against the SARS-CoV-2 virus is more than 90% effective. Walt Disney's business is suffering deeper coronavirus cuts than most companies since the pandemic has strangled the income streams from both its theme parks and movie businesses. Any sign of a return to normal consumer behavior in 2021 and beyond counts as market-moving news for Disney, and the development of highly effective vaccines definitely falls in that category.

A purple charting arrow bounces skyward off a black trampoline.

Image source: Getty Images.

Now what

There are actually several ultra-effective COVID-19 vaccines in the works, but Disney investors had been holding their breath for so long that we only saw one huge sign of relief last month. Disney shares are still trailing behind the broader market in 2020. Management was quick to adjust their long-term business plans in order to fit a shifting media market, throwing Disney's weight behind a serious video-streaming effort while cutting costs in a thousand and one ways. The fallen giant will surely get back on its feet again, and you should buy Disney stock at these low prices.