A sub-federal issue is the debt of a constituent region of the Russian Federation — an oblast, krai, republic or federal city. The loan is backed by the regional budget rather than the federal one, so these bonds normally yield more than OFZ of comparable maturity. That difference is precisely what the investor is paid for a region's creditworthiness differing from the country's.
Almost every sub-federal issue amortises: the face value is returned in instalments on a published schedule rather than in a single sum at the end. As a result the effective investment horizon is shorter than the formal maturity date, and the coupon amount shrinks along with the outstanding face value — at an unchanged rate the absolute payment gets smaller each year.
Liquidity is markedly lower than for federal issues: placement volumes are smaller and the bonds often settle with institutional holders until maturity. In practice this means a wide spread between bids and offers, and days with no trades at all. For an investor prepared to hold to maturity this is no obstacle; for one who expects to exit early it matters a great deal.
Credit quality varies between regions, and rating agencies assess them separately from the sovereign level, weighing budget stability, debt load and dependence on federal transfers.
