What happened

Shares of e-signature leader DocuSign (DOCU -0.26%) are up a lucky 7.77% as of 12:05 p.m. ET.

The stock appears to be responding favorably to a Securities and Exchange Commission (SEC) filing -- just highlighted by TheFly.com last night -- that shows the CEO of the company purchased $5 million worth of DocuSign stock earlier this week.

Person in suit peeling off $100 bills.

Image source: Getty Images.

So what

Details on the purchases can be found on a Form 4 filing with the SEC. There it is stated that DocuSign CEO Daniel Springer made four separate purchases of his company's stock on Tuesday, March 15.  

In total, Springer bought 66,882 shares of DocuSign at prices ranging from as low as $73.63 to as high as $76.45 per share. The sum total of these purchases worked out to just under $5 million -- and grew Springer's stake in the company to just under 140,000 shares.

Now what

That's nearly twice as many shares as the CEO owned on Monday, before he began snapping up shares of DocuSign stock that had been placed in the bargain bin. The CEO's purchases were propitiously timed, too. With DocuSign stock now selling for more than $94 a share, Springer has booked about a 25% profit from his investment in just three days' time -- and he may not be done buying yet.

Recall that the last time we saw this CEO embark upon a personal-portfolio stock-buying spree as big as this one, he was happily paying prices well in excess of what DocuSign stock costs today -- $138 a share and more. That both explains why Springer found DocuSign's recent sell-off too good a deal to resist, and why he might be more than willing to keep buying even at today's higher prices.

Outside investors should consider following the CEO's example.