Stock markets are undergoing a seasonal setback that could see 15 percent wiped off the major indexes, but the real risk of a double dip won't appear until 2011, Robin Griffiths, technical strategist at Cazenove Capital, told CNBC Monday.
"The risk of the double dip is in 2011, so all we've got now is a risk of a seasonal setback… this is the weakest season of the year now," Griffiths said.
"Traditionally September is the weakest month in the year and you make a low in October. So I'm going for the normal seasonal deviation, which gives us a risk of about 15 percent (decline)," he added.
- Watch the full interview with Robin Griffiths above.
The seasonal slump won't drag markets back to their lows of March 2009, which would count as a double dip, according to Griffiths.
"The economic numbers suggest if there's going to be a double dip, that takes place in 2011 and of course governments will be trying everything they can to stop that happening," he said.
Griffiths reiterated his view that stocks are in a long-term secular trend which peaked ten years ago and has been in decline ever since. In the long-term trend there have been numerous cyclical bull periods, such as the one that peaked in April, he said.
"Then we've had a big fall, we had a mid-summer rally. That's all that's ended recently, was the mid-summer rally," Griffiths said.
Click here to read an alternative view on the outlook for the markets.