On an overall basis, healthcare stocks are weathering the current market storm better than most. Some healthcare stocks are even rising while the market is falling, especially those of companies developing diagnostic tests and experimental vaccines and drugs targeting COVID-19, the disease caused by the novel coronavirus.

But I think that the most intriguing stocks right now aren't the ones that are defying gravity. Instead, my view is that the stocks that look especially attractive are those that have taken an overdone shellacking with the market downturn. Which healthcare stock could emerge as the biggest winner from the stock market crash? My pick is Exact Sciences (NASDAQ:EXAS).

Laboratory flask with a gold dollar sign inside it

Image source: Getty Images.

Hit harder than most

Exact Sciences shares have plunged nearly 40% from the highs set earlier this year. To put that drop in perspective, the S&P 500 index is nearly 19% below its 2020 high level while the Health Care Select Sector SPDR ETF (NYSEMKT:XLV) has fallen 12% off its high mark.

Why has Exact Sciences stock been hit harder than most? The answer is that the molecular diagnostics company decided to sell $1 billion worth of senior convertible notes in late February, just as coronavirus worries began to really intensify and take a toll on the overall stock market.

Issuing senior convertible notes isn't a bad way for a company to raise additional cash. That's especially the case when interest rates are really low. Exact Sciences will only pay annual interest of 0.375% on its notes. It's borrowing money at a dirt cheap price.

The downside, though, is the convertible aspect of senior convertible notes. The notes mature on March 1, 2028. Noteholders will be able to begin converting their notes to shares of Exact Sciences -- 8.2076 shares for every $1,000 held in notes -- beginning Sept. 1, 2027, without any restrictions and sooner if certain thresholds are reached. That could mean that a lot of dilution is on the way.

However, the conversion price is $121.84 per share. That's close to the record high for Exact Sciences set last year. The stock has a long way to go to reach that level.

Business as usual

I think, though, that Exact Sciences' share price will be much higher than $121.84 well before September 2027 rolls around. Before the huge plunge in recent weeks, Wall Street analysts predicted the stock would rise to nearly $124 per share within the next 12 months.

That level of optimism doesn't seem overdone considering how well Exact Sciences is performing. The company absolutely trounced analysts' estimates in its Q4 results announced in February. Exact Sciences' revenue soared 60% year over year to $296 million. It even posted earnings of $0.54 per share, although the bottom line was boosted by a big income tax benefit.

Most importantly, Exact Sciences should keep its strong momentum going. The company looks for full-year 2020 revenue growth of close to 86%. Sure, a lot of that growth will come from Exact Sciences' acquisition of Genomic Health. However, colorectal cancer DNA test Cologuard will also generate strong sales growth.

None of the factors that are dragging down the overall stock market should impede Exact Sciences' growth in any way. Patients and physicians aren't going to decide not to move forward with cancer screening because they're worried about the coronavirus. Super-low oil prices aren't going to make one iota of difference to the company's business prospects.

Exactly the kind of stock to buy right now

The bottom line is that Exact Sciences is as attractive now as it's ever been. And with a good chance of its liquid biopsy for liver cancer winning FDA approval later this year, there's a pretty good argument to be made that Exact Sciences is in a stronger position for growth than in the past. But the healthcare stock is trading at a significant discount to its level from just a month ago.

Warren Buffett's mentor, Ben Graham, wrote about a fictional person he called Mr. Market. Sometimes Mr. Market is completely irrational. He might buy a stock at a price well above what the stock is really worth. At other times, he might sell a stock at well below what a stock is really worth.

I think we're seeing Mr. Market sell Exact Sciences at a bargain price considering the company's growth prospects. But when he regains some rationale thinking, he'll be willing to buy the stock at a much higher price. Exact Sciences is exactly the kind of stock to buy right now with the stock market crashing.