Why not? As others have already explained to you, the BTC market cap is just a product of the price of 1 BTC and the total amount of coins available at that time. Every day approximately 900 new BTC are mined, so the MC increases even if the price stays the same or decreases. If we were to take the example of keeping the price of BTC at current values until the end of the year - and in the next 10 months the circulating supply increases by 270 000 BTC (27 000 per month), it would mean that MC at the end of the year increased by a total of $13.5 billion.

But of course if the price reaches $100k it will also mean that the MC has doubled - which is nothing unrealistic considering how fast the price has increased from $10k to $50k.