"People familiar with the matter"... They're usually important. On Friday they said Fitbit hired an investment bank to help find a buyer. Investors didn't care about the lack of official-ness to the headline, and snatched up stock on hopes they'd benefit from an acquisition (companies tend to buy other ones for an amount higher than the current share price).
368 calories burned, 982 steps taken... and a 12% stock price jump. That was Friday, but Fitbit has fallen 90% since 2015. Back when Fitbit and Jawbone were in their prime leading the wearable devices game, things were different. Now Fitbit is squeezed on both sides:
Where are the synergies?... Fitbit lost money each year since it pivoted to smartwatches to compete with Apple. For another company to acquire Fitbit, it must use Fitbit's hardware, software, and people to make money better than Fitbit did (aka find "positive synergies"). Tying Fitbit more closely to Google's Android operating system could do that. Or plant fitness-tracking chips into Nike shoes? We're idea people.