Base currency
The asset being priced in a trading pair — the first symbol, as BTC in BTC/USDT.
In the pair BTC/USDT, bitcoin is the base and the price shown is how many USDT one bitcoin costs. Coinmico converts every pair's quote currency to US dollars before combining trades into an index, so a base asset priced in KRW, EUR or ETH contributes on the same footing.