Workhorse Group Inc. (WKHS) shares had an eventful Monday, initially climbing before reversing sharply lower after the company's 1-for-12 reverse stock split officially took effect.

What Happened: The reverse split kicked in at Monday's market open, with the stock trading on a split-adjusted basis for the first time. Stockholders had approved the move back on Nov. 25, giving the board authority to implement a reverse split at any ratio between 1-for-8 and 1-for-12.

The board opted for the maximum 1-for-12 ratio, shrinking outstanding shares from approximately 26 million down to roughly 2.17 million, subject to adjustments. The company isn't issuing fractional shares, instead rounding any fractional amounts up to the nearest whole share.

According to Workhorse, the reverse split is designed to help the company satisfy Nasdaq's minimum share-price requirements in connection with its proposed merger with Motiv Power Systems. That said, the company cautioned there's no guarantee the move will accomplish that goal.

The WKHS ticker symbol remains the same, while the new post-split CUSIP number is 98138J503. All outstanding options, warrants, restricted stock, and restricted stock units will be adjusted proportionally to reflect the split.

Price Movement: Workhorse shares were trading 18.48% lower at $7.64 at the time of writing, according to market data.