The stock market took a pause on Tuesday, losing its upward momentum from earlier in the week. Efforts on Capitol Hill to try to expand $600 stimulus check payments appear to be locked in political debate, disappointing investors who wanted to see a bigger boost to the U.S. economy. The Dow Jones Industrial Average (DJINDICES:^DJI), S&P 500 (SNPINDEX:^GSPC), and Nasdaq Composite (NASDAQINDEX:^IXIC) all fell back from their Monday records.

Index

Percentage Change

Point Change

Dow

(0.22%)

(68)

S&P 500

(0.22%)

(8)

Nasdaq Composite

(0.38%)

(49)

Data source: Yahoo! Finance.

Several stocks posted much larger declines than the broader market. Arcturus Therapeutics (NASDAQ:ARCT) was the big loser on the day, losing almost half its value. Meanwhile, Blink Charging (NASDAQ:BLNK) held up slightly better, but it also faces questions about where the stock will go from here.

Arcturus can't deliver with game-changing coronavirus vaccine trial results

Shares of Arcturus Therapeutics were down 54% on Tuesday. The biotech stock had wowed investors with the promise of a coronavirus vaccine, but the initial early-stage results of studies looking at its effectiveness didn't tell the story that shareholders had wanted to hear.

Four vials labeled COVID-19 vaccine.

Image source: Getty Images.

To be clear, Arcturus's news wasn't all bad. The company's ARCT-021 vaccine candidate did help patients produce neutralizing antibodies. However, ARCT-021 didn't produce as many neutralizing antibodies as competing vaccine candidates from other drugmakers.

That's bad news for what some saw as a potential competitive advantage for Arcturus: the possibility of a one-dose vaccine. Some stock analysts believe that ARCT-021's efficacy could be so low as to not even be in the same ballpark as other vaccines.

Arcturus will continue to collect data and will run phase 2 trials in Singapore. However, the stock has lost its momentum, and shareholders don't seem willing to give Arcturus the benefit of the doubt like they were earlier this month.

Blink falls despite a new deal

Shares of Blink Charging finished lower by nearly 14% on Tuesday. The company fell in the cascade of electric-vehicle stocks despite offering some positive business news.

Blink announced that medium-duty and heavy-duty electric-vehicle manufacturer Lion Electric would offer the full line of Blink's electric-charging equipment and related services as part of its own sales operations. Lion has reached out to school systems and private bus companies to sell all-electric school buses, and Blink sees the opportunity to expand its network by partnering with Lion in serving this key and growing niche.

Yet many investors are afraid that Blink has gotten ahead of itself. Even with the vast growth opportunities the company has, Blink's market capitalization had soared to $1.5 billion. In order to justify that kind of valuation, Blink will have to tap into a huge percentage of its addressable market before competition can come into the space -- and that's a tall order given the amount of activity in the electric-vehicle industry right now.

It's inevitable that a massive infrastructure of electric-charging stations will someday be available around the world. The question is what companies will put it in place, and today, shareholders are a bit less confident that Blink Charging will play a major role in getting the job done in the long run.

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.