Shutter speed can be seen and you did a great job describing it!
Leslie, Esther, and Carol all guessed exactly right! The shutter speed was 1/125th of a second. As a rule of thumb I use 1/60th of a second to avoid camera shake and 1/125th of a second to stop motion. For a little boy who moves quickly, faster is always better!
If you notice the tulips in the corner of the frame are in focus, which is a good indicator that it's not my aperture creating the blur of his hand and the tulips.
Shirley noticed the light. The farmer's market is under a freeway which gives beautiful diffused, indirect light.
I'm keeping this photo, even with the blur. His face is sharp and that's what matters to me! Thanks for playing along.