I just spotted on
www.howtobuygrin.com that Kucoin is listing Grin today
"Trading pairs include GRIN/BTC, GRIN/ETH and GRIN/USDT. Buying starts Jan 24, 2019, 17:30 (UTC+8), selling starts Jan 24, 2019, 18:00 (UTC+8) and withdrawal opens Jan 26, 2019, 18:00 (UTC+8)."
My favorite grin exchange at the moment is ChainRift, I wish there was more volume...