Tether’s USDT, worth over $155 billion, has commanded a near-monopoly over the stablecoin market for nearly a decade.
Earning $13 billion in profit last year, the most transaction volume of any crypto asset — including BTC itself — and benefiting from its asset manager joining the presidential cabinet of Donald Trump, many people doubted any stablecoin could ever compete.
However, for the first time in history, the world’s largest stablecoin issuer is reckoning with serious competition in the form of Circle.
Circle has advanced its USDC remarkably this year, and Protos has compiled data on three metrics by which it has gained ground against Tether.
For the first time in history, the world’s largest stablecoin issuer is reckoning with serious competition.
Although Tether remains the market leader and retains a dominant share of tokens outstanding, search queries, and trading volume, Circle’s growth rates highlight some areas in which it is gaining ground.
At the end of the day, the most important metric by which to rank a stablecoin issuer is its market cap share. By this metric, USDT remains the leader with 61.5% of the $253 billion market.
USDC, in second place, has a 24% share.
Still, Circle’s growth is nonetheless impressive.
Circle gains ground on Tether in 2025
Since the beginning of the year, Circle has increased USDC’s circulating supply by 40.4%. That compares to USDT’s 13.6% increase over the same period.
Specifically, USDC’s circulating supply has grown from just over 43.7 billion to more than 61.4 billion. USDT outstanding has grown from 137 billion to just over 155.7 billion.
This is the first metric of Circle’s outperformance.
Second, worldwide Google search queries for USDC have also grown 3% this year from 64 to 66. USDT, a much more popular term on an absolute basis, has declined in popularity 25% from Google Trends’ 82 to 61 ranking.
Third, USDC has also outperformed USDT in fiat trading volume growth rates. Although USDT remains the most voluminously transacted digital asset on an absolute basis, USDC has captured a bit of USDT’s market share in 2025.
A snapshot from Bitstamp shows the rate of decline in USD trading volumes from Q4 2024 versus the trailing three months is far slower for USDC versus USDT.
Specifically, USDC volumes ticked 0.2% down from 197 million versus USDT’s 26% decline from 851 to 628 million.
Read more: Circle vs. Tether: What’s in the reserves?
Circle IPO fuels media and valuation growth
Circle has also gained a disproportionate amount of media attention relative to its main competitor in 2025. Since January, articles mentioning USDC have grown 75% from 24,169 to 42,455 per data from MuckRack.
USDT media mentions have grown a more modest 42%, from 55,473 to 78,680.
Media growth is attributable, of course, to Circle’s IPO. Indeed, its corporate valuation has increased 10X this year from $4.79 billion to $48 billion, thanks largely to its US stock market debut.
Read more: ANALYSIS: Does the Circle IPO value Tether at $316B?
Although some of Circle’s growth has captured share from Tether, Tether has increased in value in its own right.
However, the private company hasn’t conducted any financings that update Tether’s corporate valuation from its $7 billion, pre-Trump election valuation. As a result, it’s impossible to compare the valuations of the two companies.
