Meta spent $45 billion on stock buybacks last year at $330 a share. The stock is worth $100 today after a post-earnings crash.

• Meta spent $45 billion on stock buybacks last year, paying about $330 a share on average.
• Shares in Mark Zuckerberg's company have plunged 70% this year to around $100.

Meta spent about $45 billion buying back 136 million shares last year, paying around $330 a pop. Its stock was trading around $100, or less than a third of that price, on Thursday after a post-earnings crash, suggesting Facebook's parent company massively overpaid for its own shares.

Mark Zuckerberg's social-media giant also repurchased another 100 million shares in the first nine months of this year at a cost of $21 billion, or around $210 a share - more than double the current stock price.

Moreover, Meta has spent a total of $91 billion to repurchase 377 million shares between the start of 2017 and September 30 this year, at a weighted average price of around $242 a share, a Markets Insider analysis of Securities and Exchange Commission filings shows. Those shares would cost under $38 billion — or nearly 60% less — to buy today at Meta's current stock price.

Shares of the Facebook, Instagram, and WhatsApp owner have plunged 70% this year, slashing the company's market capitalization from about $900 billion to around $270 billion. The sell-off has been fueled by mounting doubts about Zuckerberg's expensive bet on the metaverse, concerns about an advertising slowdown, and investors dumping tech stocks in favor of safer assets.

Meta's stock slump has made its past repurchases look expensive. If the company could erase all of its buybacks since 2017 and conduct them at today's price instead, they would theoretically cost $53 billion less — more than one-sixth of Meta's current market capitalization.

However, it's worth emphasizing that even if Meta could start its buybacks today, it probably wouldn't save quite that much money. Its repurchases would be constrained by the cash it has available, the trading volume of its stock, and how much buyback spending has been approved by its board. Aggressive repurchases would likely boost Meta stock as well, raising the company's cost per share.

Still, Meta may seek to capitalize on its depressed stock price, and compensate for its arguably overpriced buybacks, by ramping up repurchases now. The company is already on track to rival the 136 million shares it repurchased in 2021.

Moreover, Zuckerberg and his team had $42 billion in cash and marketable securities at the end of September, plus board approval to spend another $18 billion on buybacks, meaning they have the money and permission needed to pounce on beaten-down Meta stock.

Here's a chart showing Meta's stock buybacks since 2017: