Friday was a strong day on Wall Street, as major benchmarks finished higher by 1% to 2%. Market participants focused their attention on the April jobs report, which included a drop in the unemployment rate to 3.9%, its lowest level in more than 17 years. Nonfarm payroll gains of 164,000 weren't extremely strong, and some saw wage growth of just 2.6% as bad news for workers. Yet from many investors' perspective, weak wage growth is actually a positive, as it indicates a lack of inflationary pressure that's good for most stocks. Good news regarding several key individual companies also helped stoke favorable sentiment. Apple (NASDAQ:AAPL), Kraft Heinz (NASDAQ:KHC), and California Resources (NYSE:CRC) were among the best performers on the day. Here's why they did so well.

Apple gets more love from Buffett

Shares of Apple climbed 4% to hit a record high after Berkshire Hathaway CEO Warren Buffett reported that he had increased his stake in the iPhone maker during the first quarter of 2018. Buffett said in an interview with CNBC that Berkshire bought 75 million more shares of Apple, worth roughly $13.5 billion at current prices, and that brought the total holdings for the insurance conglomerate to 240 million shares, worth more than $43 billion. With the Berkshire annual shareholder meeting taking place this weekend, Buffett's words carry even more weight than usual, and some still believe that Apple shares are bargain-priced even at all-time-high levels.

Apple store location from outside, with palm tree near entrance, near dusk.

Image source: Apple.

Kraft Heinz looks tastier

Kraft Heinz stock rose almost 6%, adding to its gains from Thursday following the company's first-quarter financial report. The food giant suffered from weak sales, with overall revenue falling 0.3% on a 1.5% decline in organic sales. Yet adjusted earnings grew from the year-earlier quarter, and investors liked the fact that the ketchup maker held onto its pricing power even in a tough retail environment. Because Kraft Heinz is a Berkshire holding, the pre-annual meeting media blitz elicited comments from Kraft CEO Bernardo Hees, who noted that even though Buffett has left the Kraft board, he doesn't see any change in strategy going forward. Some thought that the departure might give Kraft the go-ahead to consider a major acquisition, something many investors think would be a good avenue for growth.

California Resources looks more energetic

Finally, shares of California Resources soared more than 22%. The oil company reported a surprise profit in its first-quarter financial report, due largely to stronger production figures than most of those following the stock had expected to see. Between higher production and rising energy prices, California Resources was able to make a good-sized dent in its outstanding debt, improving the health of its balance sheet in a way that could boost its ability to make future capital investments. The oil company still has further to go, but the results were encouraging for those who've stuck with California Resources through several difficult years.

Dan Caplinger owns shares of Apple and BRK-B. The Motley Fool owns shares of and recommends Apple and BRK-B. The Motley Fool has the following options: long January 2020 $150 calls on Apple and short January 2020 $155 calls on Apple. The Motley Fool has a disclosure policy.