Why Opko Health, Avis Budget Group, and Adomani Slumped Today

Thursday was another relatively quiet day for the stock market, and major benchmarks finished on either side of the unchanged mark by the end of the trading session. The Dow Jones Industrials hit another record, but the Nasdaq Composite finished down on the day. The long bull market in stocks has benefited from low interest rates, but market participants today started to speculate that further increases in rates from the Federal Reserve might come sooner than hoped. In addition, some companies suffered from bad news that sent their share prices lower, and Opko Health (NASDAQ: OPK), Avis Budget Group (NASDAQ: CAR), and Adomani (NASDAQ: ADOM) were among the worst performers on the day. Below, we'll look more closely at these stocks to tell you why they did so poorly.

Opko's slump continues

Shares of Opko Health fell another 7%, adding to its poor performance throughout 2017. Opko has had to deal with disappointment on multiple fronts, including less-than-encouraging results in clinical studies and slow starts for approved drugs. Yet even though several institutional investors have thrown in the towel and given up on the company, Opko has strong potential for sales of its chronic kidney disease treatment Rayaldee to pick up. Moreover, Opko's diagnostic testing business has good prospects as well. Although the company hasn't executed well yet, some are optimistic that the future is bright for Opko.

Avis stalls out

Avis Budget Group stock dropped almost 7% in sympathy with other rental car specialists, as analysts issued a downbeat outlook for the industry. Some had believed that with the widespread damage to vehicles caused by Hurricanes Harvey and Irma, better conditions in the used car market could lift shares of Avis and its peers going forward. Yet analysts at Morgan Stanley think that the run higher for Avis' primary competitor was overdone and cut their rating in response. Even though Avis wasn't directly the subject of that critique, it faces many of the same challenges, and it will be tough for Avis to succeed where its rivals are failing.

Adomani isn't going anywhere

Finally, shares of Adomani fell another 21%, bring its losses over the past week to about 40%. The zero-emission electric vehicle technology specialist just came public in June, and it marked the first time that a company used the new Regulation A+ process for small companies to go public. Yet the stock has been extremely volatile, climbing from an offering price of $5 per share all the way to $17 before going through some turbulent moves both up and down in the interim. Opinions vary widely about the company's business model and ability to stand up to much larger competitors, and today's move downward highlights the risk level of investing in a start-up in such a critical and fast-moving industry.

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Dan Caplinger has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.