Why Did Atlantic Power Stock Drop 11.5%?

What happened

Shares of Dedham, Mass.-based electric power provider Atlantic Power (NYSE: AT) plunged 11.5% to close at $2.31 per share in Wednesday trading -- apparently for no good reason.

The only news that emerged today was of the positive variety: A Form 4 filing with the Securities and Exchange Commission confirmed that Atlantic's executive vice president of commercial development bought two batches of 10,000 shares each of Atlantic Power stock (an "insider purchase") for prices of $2.35 per share and $2.38 per share, respectively. Both prices were above where Atlantic Power stock ended the day.

So what

That sounds like positive news -- an executive putting his own money on the line to expand his investment in the stock. And yesterday's news was no worse: A press release announced an upcoming sale, in May 2022, of Atlantic's Manchief power plant to a current customer for $45.2 million.

As Atlantic Power explained in the release, it will continue operating Manchief for the next three years, and continue "to realize the cash flows for the remaining PPA [power purchase agreement] term" before ultimately selling the plant for cash, which Atlantic will apply to "support continued debt reduction."

Now what

So why is Atlantic Power down after two days of nothing but apparently positive news? I honestly cannot say.

Perhaps the answer is as simple as this: Atlantic Power is a penny stock, trading for just a couple of bucks a share, and has a market capitalization of only $255 million, making it subject to large percentage moves on relatively tiny (in this case, just $0.30) changes in absolute stock price.

But that's just a guess. And your guess is probably as good as mine.

10 stocks we like better than Atlantic PowerWhen 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 quadrupled the market.*

David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Atlantic Power 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 March 1, 2019

Rich Smith 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.