FORTUNE — J.C. Penney’s JCP first-quarter earnings, announced today, showed a dramatic improvement, with same-store sales up 6.2% — more than expected — and its gross margin rising to 33.1%, the highest such figure since before Ron Johnson’s disastrous 16-month tenure as CEO and the return of Mike Ullman. Investors reacted with wild enthusiasm, bidding the stock up 24% to $10.41. But is this truly a comeback?

At first glance, yes. The company hasn’t delivered good sequential results in years. And with other retailers, such as Wal-Mart  WMT and Target  TGT , blaming weather for disappointing numbers, it would have not been surprising if JCP had tried the same. It was certainly reassuring to hear that the revamped home department, a real drag on the store during the Ron Johnson era, was one of the leaders.

“I don’t want to get too giddy,” says Brian Sozzi, CEO and chief equity strategist of Belus Capital, who recently upgraded J.C. Penney’s stock from a sell to a hold, “but this just validates that by going back to old-school retail principles that they could be profitable by the holiday season. You are now starting to see a light.”

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And yet it’s important to maintain perspective: The company posted an operating loss of $352 million this quarter — a bit more, in fact, than the $348 million of a year ago. And same-store sales looked good this quarter mostly because last year’s figures had swooned so dramatically, making for a flattering comparison.

In this difficult retail environment, Ullman deserves congratulations for bringing JCP back to basics. But recovery and success are not quite the same thing.