can someone tell me how the transaction work is it in USD OR Price of ETH / BTC ?
1 ETH = 900 $ TOKEN GIVEN 3000
when the price increased to 1000 $ then the token given to investor will be based on ethereum or usd ?
The tokens price is defined only by market. So, if you sold 3000 tokens for 900$ (users have spent 900$), and then the price of Ethers is increased, then, in the next moment, the price of your tokens (most probably, because it is market - there nothing is quaranteed) will stay the same in UDS - $900. Hence - in ethers - it will decrease. Because tokens price is related to real world (actual usd money), but not to some intermediate "almost-currency" like Ethers.