Julio Teheran - Sell high or is he back?

Season stats thus far: 1-4, 63 innings, 2.57 ERA, 1.03 WHIP, 59 K

Julio had another terrific performance last night (even though it was the Brewers). His ground ball rate is up from last year from 39.5% to 44% which is good news considering he is known to give up the long ball. Speaking of, his HR/FB rate is almost cut in half, going from 13% in 2015 to 7.8% thus far in 2016. He's leaving more runners on base than last year, 73% in 2015 and 78% this year. FIP is down from last year, 4.40 in 2015 and 3.67 in 2016.

Thoughts on him? Sell high while he's on (I've got a few offers on him) or should we hold and ride him out? Is he back?