IHS says that recent years have seen a drastic growth in smartwatch shipments - the market grew from 9.4 million units in 2014 to 149 million units in 2018. In just one year, shipments grew 42% from 2017 to 2018.
This rising demand for smartwatches has of course created a rising demand for displays. OLED displays are leading this segment - with around 80% of shipments in 2018 (the rest are mostly LCD displays). AMOLED display shipments were around 42 million and PMOLED shipments reached around 75 million.
RiTDisplay alone, according to IHS, shipped 32.5 million monochrome PMOLED displays to low-end fitness bands (for Xiaomi and other Chinese makers). LG Display, Apple's exclusive smartchwatch display supplier (for now, at least), shipped 16.1 million AMOLED displays.