This really is an interesting situation... I cannot come up with a really good analysis really.
I've seen that situation before, and I can't figure it out either. All I can say is that I've seen it a handful of times and that the price is still on an upward trend, so I don't sweat it...although I definitely don't get it...maybe it's the only one with real and not inflated value?
Of the list Monero is the only with a 'real' distribution (organic), some others like LTC and ETH have some decent distribution but its offset by awful concentration or premine. I would say Monero is the only real coin besides Bitcoin.
You know... with there being thousands in BTC volume traded daily. Millions of dollars a day... there is only really one reason the price is resisting the greater trends in an amazing bull market where even known scam coins are growing orders of magnitude in value.
Someone is selling.
Our bull market is being quietly held down by someone or someones selling.
I believe it's that simple.
Or on the flip side someone wants to keep the price down below the ATH to form an ascending triangle thus the blow off will be that more epic. The more pressure builds in sideways movement the higher the pop will go IMO.