You mean convert it all at once? If the STEEM price is what people are worried about, that would be apocalyptic. If my SBD were suddenly traded for Steem, I'd convert it to something else as quickly as I possibly could. I'd sell all of it, at least as long as markets existed to sell.

I hold SBD for one reason: I want price-stability. I'm sure I'm not the only one. If people want price-stability, it's price-stability they'll get, and they'll get it by rapidly exiting the Steem ecosystem.