'Shark Tank' investor Kevin O'Leary boosted his stakes in Microsoft, Amazon, and Facebook: 'You go back to what works'

• "Shark Tank" star Kevin O'Leary bet big on stocks in the final quarter of 2020.
• O'Shares Investment Advisers boosted its stakes in Amazon, Alphabet, and Facebook by more than 50%.
• O'Leary told CNBC more government stimulus could drive prices higher.
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"Shark Tank" investor Kevin O'Leary doubled down on stocks last quarter, citing a dearth of better options and the prospect of more government stimulus checks.

O'Shares Investment Advisers increased its position in several "big tech" stocks, SEC filings show. It boosted its stake in Microsoft - its biggest holding - by 27% to 250,000 shares. It also lifted its stake in Amazon by 80%, Alphabet by 56%, Facebook by 59%, and Alibaba by 61%.

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O'Leary's firm added to all 20 of its largest holdings, which also included healthcare groups Johnson & Johnson, Merck, and Pfizer. Coupled with rising stock prices, that helped to lift the value of its stock portfolio from $959 million at the end of September to $1.3 billion as of December 31.

"I can't find anywhere else to put money that's competitive," O'Leary told CNBC on Monday, highlighting that fixed-income assets could face inflationary pressure from further government stimulus.

O'Leary - whose nickname is Mr. Wonderful - predicted another stimulus package would drive even more cash into the stock market.

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"All of that liquidity speaks to owning equities and you go back to what works," he said. "I just see it as a buying opportunity and to continue with the names that have really served me well, and load up to full weightings on them."

O'Leary specifically defended his investment in Facebook. The social network continues to draw criticism for allowing hate speech and misinformation to spread on its platform, but it remains a crucial advertising tool for many US companies.

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"Yes I know we have to shut it down, it's evil, but you can't do that right now, because it's running small business in America, period," O'Leary said. "Gotta wait till we have something else."