Thread: Subjunctive mood.

Will it be correct to say "If we had bought these shares last year, we would be billionaires next year."?

The subjunctive with "would be" applies to present certainties and your example is talking about a future speculation.
If you didn't buy Yukos when it was cheap last year and now see that the price has risen you could say, "If I had bought Yukos last year I would be a billionaire by now." In your example, you're basically saying that the value of those shares which you didn't buy is currently not worth a billion but will be next year. In other words they will appreciate a certain amount. The problem is there's no way to know that. Stock prices don't automatically increase in value. They may very well but it's never certain. You could say, "If we had bought these shares last year, we could very well be billionaires next year."