Trading Rewards = Personal trading volume/Total trading volume* BUBBLE output
(Total trading volume refers to the total volume with unclaimed BUBBLE rewards)
Assume that your individual trading volume and the BUBBLE output in the pool are constant from the moment you swap till the time you claim your reward, the total trading volume is increasing or decreasing, so the number of your BUBBLE reward become less as total volume increases. If there are users claiming the rewards, their trading volume will also be removed from the pool, which means your BUBBLE rewards will increase.
Click Swap to conduct the transaction. If there is trading reward for the pair, Click Claim to collect the BUBBLE tokens.