What: Investors in XPO Logistics (XPO -2.78%) have been on a roller coaster the past few months. In May, the stock was up nearly 25% on the year, soundly beating the market. But a series of major acquisitions, and a big change in strategic direction, sent investors selling. 

The sell-off lasted nearly four months, but it's looking like the tide may have turned. After moderate gains to start the week, shares jumped 12% today, and are up 23% since Monday. The stock is still down a lot for the year, but it's an improvement from just a few days before:

XPO Chart

XPO data by YCharts.

So what: This is basically the inverse of what we wrote when the stock was close to bottoming out a few days ago. Without any material news, it's hard to point at one particular thing and say, "That's the cause."

If history tells us anything, however, it's that unpredictable momentum shifts like this can happen. If you consider the big change in philosophy from an "asset light" company to one that's actively buying and integrating shipping and trucking companies, some selling shouldn't be a big surprise, especially considering this:

XPO Chart

XPO data by YCharts.

During the past five-plus years, XPO Logistics stock has absolutely crushed it, beating the S&P 500's returns at its peak this year by more than 10 times. Considering how poorly the market has performed so far this year, a lot of uncertainty around parts of the global economy, and the change in direction at XPO Logistics, there's a good chance a lot of the selling was people "locking in" some of their huge gains during the past several years. 

That's in addition to an overall spike in trading activity:

XPO Volume Chart

XPO Volume data by YCharts.

A lot more XPO Logistics shares have been trading hands during the past few months than were trading at the start of the year. There's just been a lot of speculative volatility. 

Now what: There's a chance that some of the recent reversal is due to CEO Bradley Jacobs' words at a recent industry event, where he put to rest any concerns that he was trying to turn XPO Logistics into a UPS or FedEx, one of the big concerns some investors have raised. Jacobs made it clear that he's not looking to compete in a segment that's already loaded with dominant parcel delivery companies, but is more focused on supply-chain service, including logistics and transport. 

Jacobs has a world of experience and a strong record of success. There's no telling what happens from here with the stock -- at least in the short term -- but I wouldn't bet against this CEO in the long run. It may take some time for the strategy shift to pay off, and the company's recent spate of acquisitions isn't likely over. Plus, there's the likelihood that there will be some speed bumps with integration of these acquisitions, reducing costs, and finding better ways to leverage newly acquired assets. 

Only time will tell how Jacobs' bold new plan will work out, but I probably wouldn't bet against him.