Berkshire Hathaway shares rose on Monday after Warren Buffett’s conglomerate posted strong earnings for the fourth quarter over the weekend.

Berkshire class B shares jumped 2.3% in premarket trading, set to add to their 17% gain already this year. Berkshire closed on Friday with a $905.5 billion market value, according to FactSet.

Berkshire on Saturday posted fourth-quarter operating earnings of $8.481 billion, about 28% higher than the $6.625 billion from the year-ago period, driven by big gains in its insurance business. Operating earnings refers to profits from businesses across insurance, railroads and utilities.

Meanwhile, Berkshire’s cash levels also swelled to record levels. The conglomerate held $167.6 billion in cash in the fourth quarter, surpassing the $157.2 billion record the conglomerate held in the prior quarter.