The ASX 200 index is headed for a test of resistance at 4170 after forming a higher trough. Breakout would indicate a rally to test 4450. Recovery of 63-day Twiggs Momentum above zero would strengthen the signal. In the long term, breakout above 4450 would signal a primary up-trend, but that may be some way off. Reversal below 3990 seems just as remote but would signal another primary decline.