Can I apply transparency to a symbol as a whole – not to each of its components?

When I change the Alpha value of a symbol on the timeline, transparency is getting applied to each of the symbol's components:

That's not what I want. … I want the symbol to blend as a monolithic, single object – as a whole.

How can I do that?

Currently, the only way I would know of is to cover the symbol with a solid filled square object that's having Alpha applied. But that doesn't work if the background isn't a solid color.