Office Depot. Image source: Office Depot.

What: After some criticism from U.S. District Judge Emmett Sullivan on Thursday about the U.S. Federal Trade Commission's methods used to attempt to block a merger between Staples (SPLS) and Office Depot (ODP -0.01%), as well as a new comment from an Amazon.com (AMZN 1.74%) executive about the company's early progress as a competitor to Staples and Office Depot, investors seem encouraged that a merger could ensue.

Shares of both stocks jumped. Office Depot and Staples shares increased as much as 14% and 9% on Friday, respectively. At the time of this writing, Staple's has held its gain, but Office Depot shares are now up 10%.

So what: Sullivan asserts that the FTC attempted "to elicit false information from an Amazon executive to bolster its case," according to Bloomberg.

Further, Staples and Office Depot's key reason for a merger, which is that the two company's would be able to better compete with Amazon's rapidly growing presence in the space as a duo than they would separately, was strengthened when Amazon executive Prentis Wilson noted that "about 300,000 businesses" had already opened accounts with Amazon's 11-month-old Amazon Business service, reported Bloomberg.

Now what: A merger between the two could reinforce their competitive competitive positions as Amazon ramps up its competing business services.

But mergers are difficult to predict. Investors should be careful to refrain from getting caught up in speculation about a deal.