The Descending Triangle, also a variation of the symmetrical triangle, is generally considered to be bearish and is usually found in downtrends.
Unlike the ascending triangle, this time the bottom part of the triangle appears flat. The top part of the triangle has a downward slant. Prices drop to a point where they are oversold. Tentative buying comes in at the lows, and prices perk up. The higher price however attracts more sellers and prices re-test the old lows. Buyers then once again tentatively re-enter the market. The better prices though, once again attract even more selling. Sellers are now in control and push through the old lows of this pattern, while the previous buyer's rush to dump their positions.
HERE IS A SAMPLE CHART WITH A PARABOLIC FORMATION