Take a look at some of the biggest movers in the premarket:

Activision Blizzard (ATVI) – Activision shares jumped 2.7% in premarket trading after Warren Buffett told the Berkshire annual meeting that the company had increased its stake in the videogame maker.

Bilibili (BILI) – The China-based online gaming company’s stock slid 4.2% in the premarket after Jefferies cut its price target to $51.30 from $61.50 per share, citing Bilibili’s recent cut in its revenue outlook due to the resurgence of Covid cases in China.

Moody’s (MCO) – The credit ratings company missed estimates by a penny a share, with quarterly profit of $2.89 per share. Revenue was slightly above analysts’ projections. Moody’s also cut its full-year revenue outlook due to its expectation of continued market volatility, and the stock fell 3.6% in the premarket.

Global Payments (GPN) – The payments technology company reported quarterly profit of $2.07 per share, beating estimates by 3 cents a share. Revenue also topped analysts’ forecasts. The company also said it is making progress with a strategic review of its Netspend consumer business.

Berkshire Hathaway (BRK.B) – Berkshire posted a mixed quarter, with first-quarter earnings beating estimates as revenue fell short of Wall Street forecasts. Earnings were down from a year ago due to stock market turbulence and an increase in insurance claims.

HSBC (HSBC) – HSBC is under pressure from its largest shareholder — China-based insurance company Ping An – to break itself up, according to a source familiar with the matter who spoke to Reuters. Ping An is said to have presented its breakup plan to the bank’s board of directors.

Moderna (MRNA) – Moderna said its Covid-19 vaccine for children under 6 years old will be ready for review by a Food and Drug Administration panel when it meets in June. Moderna applied for emergency use authorization for the treatment last week.

China EV Makers – Li Auto (LI) and Nio (NIO) both reported a drop in April deliveries compared to a year ago, saying production took a hit from the resurgence of Covid in China. Rival Xpeng (XPEV), however, reported an increase in deliveries compared to April 2021. Li Auto fell 1.7% in the premarket while Nio lost 2%.