What this means?

For BABA (NYSE:BABA), we notice a call option trade that happens to be bearish, expiring in 9 day(s) on December 4, 2020. A trader bought 500 contract(s) at a $285.00 strike. The trader or institution spent $135.0K on this trade with a price of $270.0 per contract. There were 4779 open contracts at this strike prior to today, and today 2563 contract(s) were bought and sold.
benzinga.com/markets/options/20/11/18535946/understanding-advanced-micro-devicess-unusual-options-activity