This is a bullish indicator and indicates the continuation of an upward trend. The ascending triangle is a very common pattern seen in bullish markets.
In an uptrend, the first resistance is found (1) and the price reverses until it finds its first support (2). Price reverses direction and continues its upward movement until the second resistance is found (3) which is near or level to the first resistance level and also forms the horizontal line in this pattern.
The price reverses direction and finds its support slightly higher than before (4).
The pattern completes when the price breaks through the initial resistance level as set out in this pattern (5).