When the Bitcoin will reach its limit.
And it continued to grow, you think the price of Bitcoin will increase?
once it reaches 21 million the amount of bitcoins is only going to decrese due to lost wallets and such. meaning the value per bitcoin should increase gradually.
Bitcoin will not be fully mined until about year 2140.. and by then, I predict a good couple of millions will have been lost in between accidents, people dying and not giving their coins to family, in general losing coin's access forever.
Maybe by then, half the supply is lost forever, so all the economy runs in like 10 million coins.