Quote from: maarx on October 29, 2017, 05:47:42 PM

Almost 50-70 percent of lost coins, were lost via hacking.

Those are not lost coins. Hackers can still spend the coins. We're talking about coins for which we know the keys have been lost, and therefore no one will be able to spend them unless someone can ever crack 256-bit security.

Quote from: MPulse on October 29, 2017, 05:22:08 PM

I'm curious how many Bitcoins are lost for good?

There's no way to know for sure, but this thread tried to add up all the coins that they knew were lost (such as from news articles with people that lost their hard drives and any other information that they could pick up).

The most recent count I found was on page 16, and it was at BTC134,679.00144159.

Quote from: MPulse on October 29, 2017, 05:22:08 PM

or simply coins have been lost because various exchanges have shut down.

I wouldn't consider those coins lost forever. If we count getting hacked or scammed then the same coins could be lost loads of times, and they're not actually lost forever. I would count services closing down as part of this.