First halving: block reward goes from 50 #Bitcoin to 25, but it took less than 100 days for the Fiat value of the block reward to reach what it was before the halving.

Second halving: block reward goes from 25 #Bitcoin to 12.5, but it took less than 1 year for the Fiat value of the block reward to reach what it was before the halving.

Third halving (current): block reward goes from 12.5 #Bitcoin to 6.25, but it took less than half a year for the Fiat value of the block reward to reach what it was before the halving.

Fourth halving (upcoming): block reward goes from 6.25 #BTC to 3.125, but how long will it take for price to double?