Is there a move that raises speed but lowers special attack?

Question

I am playing Pokemon showdown and wanna find a move that always raises speed and lowers special attack, do you know any?

Answer 1

There are no moves like this, whether it be raising your Speed or the Targets.
Source: Bulbapedia's page on on the stat-modifying moves.

Answer 2

No

/nms boosts spe, lowers spatk:

No moves found.

Source