I pulled this from one of my favorite credit card blogs (Million Mile Secrets).
Chase has just issued its first Chase Ultimate Rewards points transfer bonus. With it, you can earn a 30% bonus for transfers to British Airways Avios points.
Through June 16, 2019, you'll get a 30% bonus when you transfer Chase Ultimate Rewards points to British Airways Avios points. The standard transfer ratio is 1:1 (in 1,000-point increments) so with this bonus, you'll get 1,300 British Airways Avios points for every 1,000 Ultimate Rewards points you transfer.
It's worth noting that the bonus is being processed by British Airways, not on Chase's side, so you'll only see the bonus Avios points once you're signed into your British Airways account. Luckily, Ultimate Rewards points transfers to British Airways Avios points are instant. And you can take advantage of the transfer bonus as many times as you'd like before the offer's expiration date.