Thanks, there's could be major effects on the other side, like negative event happened to Keith Thurman that's why the odds spiked.
I'm just curious this since this is my first time encountered this (not only on boxing), the odds spiked too much for me.
Expect that the odds will change as we go nearer to the date of match. As said by ralle14, those were typically the reasons why the odds changes and there's also a small logic to it, if the fighter has more demand expect that odds will definitely change.
It has happened also a couple of time with me, especially when the connection is not very good, so the polling rate is lower than normal and gradual variations are not shown, instead there is a spike.
Maybe it's on sportsbet's end or on their odds providers because sometimes I experience it as well but only on the live odds and I have a stable connection.
I didn't know that there's a relation having an unstable connection with odds.