My source happens to be one of two of the absolute best traders (in my opinion) I follow in the Bitcoinmarkets Subreddit (u/aa09455d). The method (in his words) based upon his March 12th comment is as follows:

It has been my theory for a while that the a hard floor for the Bitcoin price is one that results from pure hodler support and thus stripped of support from speculative holding.

I derive this by looking at past cycle bottoms and then applying a factor that is the square of the proportional increase since then of wallets with meaningful balance (> 0.01 BTC).

This methodology quite accurately projected 3k in Dec 2018 from the $190 in Jan 2015. If we further apply this to now, that gives a number of $4.8K.

Price as of Dec 2018 = $3,128

Addresses in Dec 2018 with balance > 0.01 BTC = 6.41 million.

Addresses now with balance > 0.01 BTC = 7.93 million

$3,128 * (7.93/6.41)^2 = $4,800

I think this is useful information under current circumstances as otherwise Bitcoin only touches this kind of floor about once each cycle and I certainly didn't expect reaching a price with no speculative support two months before halving. But one has got to be in tune with times.

When I last used this method in April, the theoretical floor of Bitcoin (based on this Metcalfe's variant) was $5,100. I'd be curious to see what it spits out now. I'd also be curious to see how this could be applied to HIVE and some other cryptocurrencies I trade.