That figure (net investment expenses/gains) are the "CNIL" balance.  The cumulative net investment loss (investment expenses over investment income) is a somewhat meaningless number these days.  When everybody was eligible for a $100,000 per year capital gains deduction, a negative CNIL balance reduced the amount of the deduction you could claim.  Now, it will only reduce a capital gains deduction which is claimed on Farm/fishing or some other capital gains deductions.