Shares of Uber fell to fresh lows on Wednesday as investors await the company's IPO lockup agreement to expire.

The stock slid more than 3% on Wednesday, after falling as much as 8.7% earlier in the day. The plunge caused shares to hit a new all-time low of $25.58 in intraday trading.

Wednesday is the first time since Uber's IPO in May that insiders can sell the stock and analysts have warned it could put near-term pressure on the shares. Roughly 90% of Uber's stock will be available for sale, according to analysts at MKM Partners.

Uber's lockup expiration may not be as volatile as some analysts are expecting, since many pre-IPO shareholders are underwater. The stock has fallen more than 37% since Uber went public at $45 earlier this year. Shares closed at a record low of $28.02 on Tuesday after the company reported over $1 billion in net losses in its third-quarter results.

Additionally, investors will be waiting to see if some of the biggest buyers of Uber's pre-IPO shares will participate when the lockup expires, like SoftBank, Morgan Stanley and Fidelity, among others. Wedbush analysts estimated that 763 million shares will unlock on Wednesday, with 25% of them being sold by early-stage private investors.

--CNBC's Ari Levy contributed to this story.