WHAT WOULD A PROLONGED BEAR MARKET LOOK LIKE?

WHAT-WOULD-A-PROLONGED-BEAR-MARKET-LOOK-LIKE

In 2018's bear market, which lasted 11 months, the floor price was ~ $6.4K involving multiple #DeadCatBounce with up to 80% rebounds. During this bearish phase, the percentage of supply in loss grew +20% due to the BUY/HODL at prices above ~$6.4K.
Assuming the second ATH was a dead cat bouns in a bear market, so far percentage of supply in loss has grown +6% while we had a +130% rebound to $69K. Therefore, a lengthier bear market is not out of the picture.
WHAT IF A  #BlackSwan TAKES PLACE? 
There are many possible causes for a black swan occurrence in the market. But what are the possible holding lines, assuming similar historical events?
For a nightmare scenario, my favourite bottom model is the low band of the Mayer Multiple; 0.6 X. Historically, #BTC has been lower than 0.6 * 200 MA for almost 3% of its entire history. Currently, this level is showing 29K.