Wednesday was a mixed day for the stock market, with most major market benchmarks giving up modest amounts of ground even as the technology-heavy Nasdaq Composite posted modest gains. Signs of economic sluggishness led some investors to believe that future interest rate increases might be less likely than they originally thought, and that put a damper on the positive momentum the market had generated in recent days. Some stocks posted substantial declines to hold the market back as well, and H&R Block (NYSE:HRB), PDL BioPharma (NASDAQ:PDLI), and Tutor Perini (NYSE:TPC) 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.

Image source: H&R Block.

Tax reform scares H&R Block investors

H&R Block fell 7%, adding to its declines since last week's presidential election. President-elect Donald Trump has proposed a tax plan that would dramatically simplify return preparation for millions of Americans, and investors fear the resulting simplification would lead many of H&R Block's customers to go back to preparing their own returns. Analysts at Morgan Stanley downgraded the tax-preparation stock from overweight to equal weight, citing the fact that the planned repeal of the Affordable Care Act would also take away penalties for not having coverage, which involve one of the most confusing aspects of tax preparation. Unless the Trump administration is unexpectedly slow in getting tax reform through Congress, H&R Block could find that the coming tax season is its most favorable for a while.

PDL BioPharma taps the capital markets

PDL BioPharma plunged 18% in the wake of the company's announcement Tuesday night that it would seek to offer $150 million in five-year convertible senior notes. The financing move came after the holding company for equity interests, products, royalty agreements, and debt financing for the biotech, pharmaceutical, and medical device technology industries saw its stock climb following the election, and PDL BioPharma was quick to take advantage of the opportunity to raise capital under more favorable conditions. Investors had the typical negative reaction when faced with potential future dilution, but of more importance is the fact that its formerly reliable stream of dividend income has been suspended at least until PDL BioPharma can determine how to move forward more aggressively in its search for further growth.

Tutor Perini gets bad news from analysts

Finally, Tutor Perini sank 10%. The construction company suffered another analyst downgrade on Wednesday, marking the second in just two days. Analysts at Iceberg Research said the stock could fall by more than half, citing its possible reduced ability to bid successfully on contracts in a way that will maximize profit going forward. Interestingly, though, today's decline gives back only about half of the gains Tutor Perini has enjoyed in the past week, with investors having previously believed that improved prospects for companies with ties to infrastructure construction activity would benefit from the results of the election. Investors will have to wait until 2017 to see whether Tutor Perini can take advantage of predicted improvements in business conditions to add to its upward move so far this month.

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