In addition to making sure the dates correspond you'll want to make sure that you're comparing numbers using the same basis of accounting (accrual, cash, modified cash).
On the Form 990, the realized gain (loss) is usually reported on Part VIII. Unrealized gain (loss) is usually reported on Part XI, Line 5 (and not necessarily part of revenue).
Depending on the situation, Part IX, Line 4 may also include those benefits provided to Officers, Directors, Trustees, Key Employees and other Employees and therefore not reflected in Part IX, Line 9. Part IX, Line 9 could include several other items such as employee events.
With that said you probably won't reconcile between the two just by looking at the forms. I'm not saying that it's impossible but you're going to need more information to be able to reconcile. I hope this helps.
