Burry's Scion Asset Management owned call contracts against 350,000 shares of UnitedHealth, with unknown value, strike price or expiry, according to the filing.

The Omaha-based conglomerate bought more than 5 million shares in the healthcare firm for a stake worth about $1.6 billion at the end of June.

Burry's Scion Asset Management owned call contracts against 350,000 shares of UnitedHealth, with unknown value, strike price or expiry, according to the filing.

One indisputable fact is just how cheap the stock has become.

The advance came after Buffett's conglomerate Berkshire Hathaway revealed a stake of 5 million shares, worth about $1.6 billion.