Currently, the smallest unit of bitcoin is Satoshi based on bitcoin currency recorded on the blockchain. Satoshi is one hundred millionth of a single bitcoin (0.00000001 BTC). so applying the smallest unit to measure it rear can't feel the change of price for 1 Satoshi as if the fluctuation in BTC price.
The transfer fee also can be very low. one Chinese person tries successfully one experiment only paying 1 Satoshi to transfer bitcoin.
I believe that Bitcoin, as current fiat currency, will become a popular currency with high liquidity in the future.