Bitcoin is the biggest digital asset with a total market value of more than $15 billion. It also has the biggest fan base in the world. But these figures are not enough to make it the king of coins.

If you think Bitcoin (BTC) is the most used virtual money in the world today - think again. Yes, the crypto accounts for more than 70 percent of the globe's combined virtual assets in terms of market price tag, but based on CoinMarketCap's latest data, Tether is the real deal.

Tether has the biggest daily trading volume: more than $21 billion compared to Bitcoin's $16 billion. Tether's total market volume has surpassed that of its closest rival BTC's for the first time in April and has steadily outpaced it since early last month at around $21 billion a day, latest data showed.

In terms of trading volume, Tether plays a very crucial role in the digital currency market and a gateway from conventional fiat to the electronic stratosphere in many regions like China, where virtual currency exchanges are outlawed.

Based on recent research, Tether is used in more than 80 percent of all crypto transactions on on Huobi, 40 percent on Binance - two of the biggest digital currency exchanges in the world. Around 70 percent of total volume in crypto trading comes from the Asian markets.

With the aggressive stablecoin's monthly trading numbers which are 18 percent higher compared to that of BTC, Tether is one of the main reasons why government finance regulators treat cryptocurrencies with caution in the midst of mounting worries of market manipulation.

According to ConSenSys financial tech co-head Lex Sokolin, without Tether's presence in the crypto market, traders "will lose a daily trading volume of about $1 billion or even more." Sokolin said that some of the trading's potential patterns may start to chip away without Tether in the picture.

Since July this year, the number of Tether transactions has soared from just 18,000 a day to a whopping 187,920 as of September 10, Coin Metrics survey showed. These transactions now translate to 25 percent of total Tether activity.

Last April, crypto experts bared that 75 percent of Tethers are covered by cash and short-term securities. Before this, the stablecoin had a 100 percent reserve, they said.

Tether traded at 1.003637 US dollar during pre-market sessions yesterday and in the next five hours, the stable coin dropped as low as 0.9951 USD following a 0.85 percent decline.