It's no secret that Bitcoin is a scarce resource, and as time goes on, the amount of available Bitcoins will continue to decrease. With over 18 million already in circulation, it's not surprising to hear that a significant amount of these coins are either held by disciplined, long-term investors or are simply lost forever.
The fact that over 50% of Bitcoin hasn't moved in 2 years is a testament to this belief. It shows that many investors are indeed in it for the long haul and see Bitcoin as a viable store of value.
What's interesting to note here is that the scarcity of Bitcoin is what drives its value. The fact that there will only ever be 21 million Bitcoin in existence means that as demand for it increases, its value will, too. This is what makes it such a unique and valuable asset, and it's why so many people are investing in it today.