Srouts folding

I have 9 sprouts in small cups that are outside. I leave them out there all the time now and they get I'd say about 8 hours of direct sunlight a day. But a couple of the larger oneshave their upper pair of leaves starting to fold together. My camera is dead, but I used this picture because this is about the stage of growth, except the serated leaves are folding vertically. Is this from lack of sun, nutrients, or what? and what should I do?

It could be water, but I'm not sure.

You mean the leaves are folding up like taco shells?
If so it's heat.
My lil ladies did the same thing until i put them on a 18/6 light schedule to give them some time for the heat to dissipate.

The two mleaves are staying green, just folding upward together like.... praying hands?