What happened

The crazy oil market dynamics of the past few days have had some pretty strange effects on a number of stocks -- not least the oil shippers. With oil prices going negative, demand for storage space for oil shipping, and for tankers in which to store oil until prices get back to normal, has exploded, sending shares of oil tanker stocks flying, both here and abroad.

Case in point: Shares of UK-based tanker operator Torm (TRMD -0.40%) ran up more than 78.5% between Friday and close of trading Tuesday. But today, those same shares are tumbling -- down 29% as of 11:45 a.m. EDT.

Oil tanker foredeck painted red

Image source: Getty Images.

So what

Is there a reason for this?

Possibly. In fact, there could be a couple of reasons. For one thing, in the oil market, focus is shifting from futures contracts for oil to be delivered in May (that's the one where prices went negative) to contracts for oil to be delivered in June (by which time the market may have rationalized). At per-barrel prices of $14.30 (for WTI crude) and $20.39 (Brent), oil may not look expensive, exactly, right now -- but at least those prices aren't negative. For the time being, at least, oil producers don't need to worry about literally having to pay buyers to take oil off their hands.

At the same time, a tweet from President Trump this morning, threatening to "shoot down and destroy" Iranian warships if they "harass" U.S. vessels in the Persian Gulf, is raising tensions in that key oil-producing region, raising investor worries, and helping to raise the price of oil as well.

Now what

Result: somewhat less demand for oil to be transported (because it's now a bit more expensive), and somewhat less demand for oil to be stored in tankers as well (because there's at least some money to be made from selling it rather than storing it).

Secondary result: a lower share price for oil tanker companies like Torm.

It's worth pointing out, however, that despite today's fall in share price, Torm stock is still up 24% in the past three trading days. With a share price of less than three times trailing earnings right now, I wouldn't be surprised to see Torm go up some more.