Shares of Workhorse Group dropped more than 50% at one point on Tuesday after the company was passed over for a key contract from the U.S. Postal Service.

Amid heightened volatility, the stock was halted multiple times during the last half hour of trading, before ultimately finishing the session with a 47.5% loss.

The U.S. Postal Service awarded the first part of the 10-year, multi-billion dollar contract for modernization of the postal delivery vehicle fleet to Oshkosh Defense. The initial investment will be $482 million.

Workhorse makes electric vehicles focused on last-mile delivery. The company currently has partnerships with UPS and FedEx Express, among others.

The U.S. Postal Service contract award decision was drawn out over several years after a series of delays. The contract was seen by the Street as an upside catalyst for pre-revenue Workhorse Group.

In a recent note to clients, BTIG said that Workhorse securing a portion of the USPS contract was part of the firm’s base case scenario. The firm has a buy rating on the stock.

Despite the stock almost getting cut in half on Tuesday, shares are still up 347% over the last year.

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