Does Garmin really have 78% of the GPS watch market?

No. Garmin has around 77.9% of the devices Runalyze tracks specifically, a platform used mostly by serious, data-focused athletes, not the wider consumer watch market.

Which brand is growing fastest against Garmin?

Coros. It has grown from near zero in the 2010s to around 5.8-5.9% today, already ahead of Suunto and Polar individually.

Is there any other data confirming Garmin's lead?

Yes. Data Runalyze shared directly with the5krunner, measuring linked accounts rather than device files, puts Garmin at roughly 47%, still the clear leader by that measure too.

GPS watch market share Archives -

Garmin accounts for around 78% of the GPS watches tracked by Runalyze, the largest share by…