An assortment of TwitterElon Musk is being sued by shareholders for failing to declare that he bought significant shares in the social media firm in the correct timeframe.

It Tesla and SpaceX CEO revealed on April 4 that he had amassed a 9.2% stake in Twitter, leading shares to soar as investors viewed the move as a vote of confidence.

However, his disclosure might have come too late.

The Securities and Exchange Commission must be notified within 10 days of investors taking a greater than 5% share in any company, according to Federal Trade Laws.

Musk, who bought Twitter stock in January 2013, allegedly reached this milestone on March 14th, meaning that he must have informed SEC by March 24,

Musk representative the richest person in the worldCNBC reached out to the company but they did not respond immediately.

It lawsuit, filed Tuesday in New York by law firm Block & Leviton on behalf of several Twitter shareholders, alleges that Musk was able to buy up more Twitter stock at a deflated price in the period between passing the 5% threshold and publicly disclosing his stake.

A half-dozen legal and security experts experts have told The Washington Post thatMusk could have earned $156million by delaying his plans.

Twitter stock rose 27% in April 4. After Musk disclosed his 9.2% stake worth nearly $3 billion, Twitter’s stock soared 27% on Apr.

Investors who believe they were denied potential gains if Musk had disclosed his shares earlier have filed a class action lawsuit.

In a statement, Alon Kapen (a Farrell Fritz corporate transaction lawyer) stated that Musk failed to file the required 10-day deadline for Sections 13(d and 13(g of the Securities Act of 1933 in order to report 5% ownership of a public corporation.

Kapen explained that Kapen was able to purchase additional shares for an additional 10 days (he increased his ownership by an additional 4.1%) during this time, before the spike in share prices that took place on April 4, when he announced his holdings).

Musk stated that he had also planned to be a board member of the company after his tweet stake was disclosed. Musk has now decided to not take up the position for unknown reasons.