What happened? Shares of molecular diagnostics specialist Co-Diagnostics (NASDAQ: CODX) are dropping sharply on Monday and were down by 10.3% as of 3:01 p.m. EDT, after falling by as much as 12.4% earlier today. There was no company-specific news that caused the sell-off, but we can probably attribute Co-Diagnostics' losses on the market today to bearish commentary from a Wall Street analyst. So what Maxim analyst Jason McCarthy downgraded Co-Diagnostics to hold from buy. For what reason? Last year, the company benefited immensely from its coronavirus-related efforts. Co-Diagnostics reported record fourth-quarter 2020 revenue of $27.1 million, largely thanks to its Logix Smart COVID-19 test. For the full fiscal year 2020, which ended on Dec. 31, 2020, the company's top line came in at $74.6 million, compared to the roughly $215,000 it reported during the fiscal year 2019. Image source: Getty Images. However, McCarthy believes that the growth the company's revenue experienced last year thanks to the sale of its coronavirus testing solutions has peaked. The analyst expects much less impressive revenue increases in the current fiscal year. McCarthy also believes Co-Diagnostics' success in the coronavirus testing market is already baked into its stock price. Now what While it's always wise to take analyst recommendations with a grain of salt, in my view, McCarthy is onto something. As more people worldwide receive vaccines for COVID-19, the need for test kits for the disease will decrease. And given that this market is highly competitive, these developments will hinder Co-Diagnostics' top-line growth in the short term as the company finds other ways to generate strong revenue. In the meantime, Co-Diagnostics stock will likely underperform the market. With this backdrop in mind, it might be best for investors to stay away from this healthcare stock for now. 10 stocks we like better than Co-Diagnostics, Inc.When investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Co-Diagnostics, Inc. wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of February 24, 2021 Prosper Junior Bakiny 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.Source