That sort of long sustained rally is normal only during the last explosive climax to a mature bull market.
So the rally that started this May is unusual. It is the first sustained uptrend since the market collapsed after the February 2000 Budget.
The classic pattern in these circumstances is a strong rally lasting two to three months, driving prices up by 25-30 per cent, followed by a short sharp correction of say, 10-15 per cent as the early bulls book their first profits in years.