This article suggests the passage of sufficient time with or without a full 20% market loss can create "bear market" conditions.
"For most investors the enemy is time. Whether you are a younger investor still accumulating assets or a pre-retiree about to depend on your nest egg for income or a retiree already doing so, bear markets eat up your most precious commodity – time....So, is this already a bear market? If we are measuring it for the S&P 500 in terms of price the answer is no. But in terms of time? I think, for a lot of people, we’re already there. For most people it’s been two years of no gains and for some more adventurous investors, a lot worse....As to whether this will turn into recession and another big, bad, bear, that is something that can’t be said with a high degree of confidence right now."
From:
http://www.alhambrapartners.com/2016/01/23/is-this-a-bear-market/
