After his first amazing tourney run, Brad Stevens and Butler agreed on a contract extension running through the 2021-2022 a season that pays him $750,000 a year, has other incentives which he hit out of the park last year with a another run to the finals. In addition to his salary, he make more cash from camps and appearances.
Also, he has a young team this year, but Butler will be in line for a post-season run next year.
IOW, Stevens is set at Butler, until a dream job opens up. Would guess that there are probably less than 10 programs, that could lure him at this point -- maybe just 5. When one of those jobs opens and a massive offer is made, he will likely leave. Until then, he is not going anywhere until Duke, UNC, Kentucky, Indiana, Kansas, UCLA offers.