As Fitbit soars, what's the top 'wearable' stock?

UP by Jawbone (L) and Fitbit (R).
Source: Jawbone (L) | Fitbit (R)
UP by Jawbone (L) and Fitbit (R).

It was quite a debut for fitness wearable maker Fitbit. The stock opened Thursday more than 50 percent higher from it's IPO price of $20 a share.

In terms of first-day performance, that makes it one of the 10 best debuts of 2015.

Fitbit highlights a booming wearables market. Booming is putting it lightly. The number of devices shipped this year is expected to surge by 173 percent to 72.1 million, according to IDC.

Gartner placed the size of the wearable technology market for 2014 at $8.6 billion and Fitbit was 8 percent of that.

But a pie that big can't just belong to Fitbit devices and the new Apple Watch. So who else stands to benefit? And will this Fitbit stock surge last?