Electric vehicle charging company EVgo Inc. saw its stock plummet around 25% in Tuesday's pre-market trading, following the announcement of a major secondary share offering by its largest shareholder LS Power Equity Partners IV.

According to the company filings, EVgo Holdings LLC, an affiliate of LS Power which currently owns a 66.5% stake, plans to sell 23 million shares of EVgo's Class A common stock in an underwritten offering. This accounts for around 8% of EVgo's total outstanding shares.

LS Power, an early investor in EVgo which acquired the company in 2020 before its public debut, will receive all the proceeds from this share sale. The offering itself will not raise any new capital for EVgo's operations or expansion plans. However, the significant increase in outstanding shares is expected to massively dilute the holdings of existing investors, driving the steep sell-off seen in the stock price.