Pre nerf stuart could.
Post nerf stuart doesn't beat anything even remotely as expensive as itself.
The only things in that price range are Luchs, an AI tank, and Puma, a light vehicle hunter so neither would be fair comparisons. The Puma also has other weakness, such as having atrocious anti-infantry performance and only 25 armour, so it dies easily to flak, light cannon, and even HMGs, while the Stuart has 80 armour, giving it more than 50% chance to deflect Ostwind shots.
In any case you should look at the pen values of the Ostwind before making such contrarian claims. The Ostwind doesn't even threaten a T70 with its barely 50% pen chance, puny 40 damage, and chance of missing a moving light tank (high speed + small target size + low Ostwind accuracy). A T70 would need to stand still for more than 20 seconds for an Ostwind to be able to kill it.
That's one of the major problems with Ostwind right now - it's really terrible vs Light Tanks, and it can only win (while losing more than half health) if your opponent's light vehicle stops and stands still in a 20+ second face-off.