The VIX measurement of volatility might be headed back toward the normal range, but there have still been some monster one-day moves this month.

Company

Date

Single-day Increase

Reason

TiVo
(NASDAQ:TIVO)

June 3

53.3%

Won court case against EchoStar (NASDAQ:SATS)

Wind River Systems
(NASDAQ:WIND)

June 4

47.0%

Bought by Intel (NASDAQ:INTC)

Jackson Hewitt Tax Service
(NYSE:JTX)

June 5

45.4%

Appointed former H&R Block CEO (NYSE:HRB) as its own new CEO

Sequenom
(NASDAQ:SQNM)

June 9

58.2%

?????

Source: The Wall Street Journal.

That's right, as far as I can tell, there's no concrete reason for the massive increase in Sequenom yesterday. The stock was flat until noon, then it steadily climbed up to the moon in afternoon trading.

We'll get to some non-concrete reasons in a second, but first some background. Sequenom lost three quarters of its value in April after the company reported that employees had mismanaged R&D test data and results for its revolutionary blood test for Down syndrome. The diagnostic test isn't on the market yet, but early indications were that the test was more accurate and/or safer than what is currently available.

The message boards were ablaze in rumors yesterday that the company was close to resolving the issue, even though, back in April, management gave no timeline for its internal investigation and said the results of retests were expected in the fourth quarter.

It looks like those non-concrete answers turned to quicksand though. Without any corroboration from the company, the stock is down double digits today.

What's a Foolish investor to do?
If you're a shareholder, it's important to remember why you owned the stock yesterday morning. Presumably, you've got faith that the test still works, despite the concern over employee tampering. Yesterday's rumors don't really change anything for you; concrete results will be out soon enough.

If you're not a shareholder, I'd keep your investing dollars away from Sequenom. If the test turns out to work, you'll miss a monster run that will make yesterday's look like a mole hill, but figuring out how likely that is to happen is near impossible. There are too many good choices available to justify investing in one that might be a value trap.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. Intel is a Motley Fool Inside Value selection, and the Fool has sold puts on it. The Fool has a disclosure policy.