Buffett invested in Heinz in 2013 and two years later, Heinz merged with Kraft Foods. He bought 326 million shares during this merger at a cost of around $24.6 billion. He has held on to that stake, which is now worth $11.4 billion.

Some of the Oracle of Omaha's most-popular buys -- as well as Berkshire's largest holding -- offer robust upside potential in 2025.

Buffett -- as well as his late great partner Charlie Munger -- would recommend avoiding leverage at all costs in your portfolio. Why? Because when the market turns (which it will inevitably do at times), the downside can wipe you out. The levered Nasdaq ETF went into a massive drawdown in 2022, and that was just one year of bad returns.