Uber Technologies Inc. co-founder Travis Kalanick has sold more than 90% of his holding in the company since the post-IPO lockup period expired on Nov. 6, securities filings show.

The share sales, which have taken place gradually since early November, equate to more than $2.5 billion worth of Uber stock, the Wall Street Journal reported.

According to a Dec. 18 SEC filing, Kalanick sold 12,790,960 common Uber shares between Dec. 16 and Dec. 18, at an average price of $29.97 apiece. Between Nov. 6 and Nov. 8, he sold more than 20,000,000 shares.

The former CEO holds 8,220,429 shares after the latest transaction, compared with 95,648,654 shares before Nov. 6.

Uber shares were down 1.3% at $30.09 during early trading in New York on Dec. 23.