(Bloomberg) -- Shareholders of Palantir Technologies Inc. will be subject to a lockup period with its direct listing, according to people familiar with the matter. This modification would make it more like a traditional initial public offering.

Up to 80% of shares will be unable to be sold on the stock market until after Palantir’s 2020 fiscal year earnings have been reported, a milestone expected in February, one of the people said. Potential sellers couldn’t sell these shares until then.

This new modification to the direct listing could help prevent sellers from dragging down Palantir’s stock in its early days of trading. Slack Technologies Inc., which went public early last year, saw its share price decline in the following months. Spotify Technology SA, in 2018, was the first large technology business to go public through a direct listing.

A representative for Palantir declined to comment.

Palantir is expected to make its public debut in late September, people familiar with the matter have previously said.

Co-founded in 2003 by Peter Thiel, the data analytics software company was valued by private investors at $20 billion in 2015 although shares have traded on the secondary market below that mark since then.

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