What happened

Shares of electric-truck maker Nikola (NASDAQ:NKLA) declined 5% on Thursday, as of 1:20 p.m. EST. The drop is a fitting end to a troubled year for the company.

So what

The stock has been in a general downtrend over the last month after an agreement with General Motors was announced and was a much smaller deal than had originally been indicated. Shares took another hit last week after Nikola said it was backing out of a deal for an electric garbage-truck fleet for Republic Services

So what does that have to do with today's drop? It's likely that some financial managers are getting it out of their portfolios for the end of the year. 

Nikola Tre semi truck crossing a bridge

Nikola Tre semi truck. Image source: Nikola.

Now what

Nikola got a big black eye this year after a short-seller report exposed some company issues, forcing founder and executive chairman Trevor Milton to resign. Money managers probably don't want to share that black eye with clients that see they own shares that have dropped almost 80% in the second half of the year. 

Investing is about looking forward, however, not back. Nikola will need to prove its plan to bring battery-electric and hydrogen-electric trucks can be successful. It will require concrete, appropriate cost numbers for hydrogen and a fueling network to be established. And first the company will need to show it can make, and sell, battery-electric trucks. That's the data investors looking ahead need to watch for next year. 

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.