Stablecoins are booming and not just in DeFi. From payments to cross-border settlements, their use cases have exploded. But with that growth comes rising concerns: how safe are these fiat-pegged tokens, really?
Blockchain security firm CertiK recently released its updated Skynet security rankings, spotlighting the most secure stablecoins in the space. The results are eye-opening, especially as more money flows into these so-called “safe” assets.
Stablecoin Adoption Is Soaring… But So Are the Risks
In just the first half of 2025, global stablecoin settlement volumes jumped 43%, hitting $1.39 trillion. That’s massive. But according to CertiK, the speed of this adoption is outpacing the security frameworks supporting it.
Behind the scenes, major security gaps, compliance shortfalls, and operational weaknesses still linger. That’s where CertiK’s Skynet rating system comes in a 6-factor framework that evaluates each stablecoin based on:
- Operational resilience
- Governance strength
- Code security
- Market dynamics
- Fundamental health
- Community trust
Let’s look at who came out on top.
Tether’s USDT Leads the Pack
Tether’s USDT takes the #1 spot, scoring 94.72 overall. Despite its controversial past, USDT has expanded circulation from $138B to $154B in just six months proving its staying power.
USDC Is Fastest Growing
Close behind is Circle’s USDC, with a score of 93.37. After securing a MiCA license and launching a successful IPO, Circle grew its supply from $41B to $61B. It may still trail Tether in size, but CertiK called it the fastest-growing major stablecoin in 2025.
PayPal’s PYUSD Is Making Moves
In third place is PayPal USD (PYUSD) with 91.47. Issued in collaboration with Paxos, PYUSD doubled its market cap in 2025 and expanded into Solana and Arbitrum, even launching a rewards program to boost adoption.
Other Notables: Sky, Ripple, and More
Here are a few more tokens rounding out the top rankings:
- USDS by Sky (formerly DAI) Score: 90.09
Now live on multiple chains including Solana, USDS has climbed to become the 5th largest stablecoin. - Ripple’s RLUSD Score: 89.89
Though not as dominant as USDT or USDC, RLUSD has maintained a clean track record with zero security incidents since launch. - Other top-10 mentions:
First Digital USD (FDUSD), USDG by Paxos, Ethena’s USDe, USDtb, and World Liberty Financial’s USD1
Security Incidents Are Still a Major Threat
CertiK’s report also dug into the darker side of the stablecoin boom. Over the past year, the crypto space suffered 344 security incidents, resulting in $2.47 billion in stolen funds. While not all directly involved stablecoins, many depegs and losses stemmed from weak security around these tokens.
Take First Digital USD, for example. When rumors swirled about insecure reserves, FDUSD’s price plunged to $0.76. It only recovered once its issuer released audited proof of reserves.
The report categorized stablecoin collapses and price drops into a few key causes:
- Price depegs (14 total):
- Compliance issues
- Poor liquidity
- Delisting
- Asset mismanagement
- Issuance halts
- Exploits (7 total):
- Vulnerabilities in token or related smart contracts
- Chain-level flaws
- Death spirals (3 total):
- Flawed token design
- Insufficient reserves
The message is clear: when it comes to fiat-backed tokens, trust in reserves and operational resilience is everything.
Final Thoughts
Stablecoins may seem safe on the surface but as usage scales, so does the need for rock-solid security and transparent operations. According to CertiK, USDT, USDC, and PYUSD are leading the way for now. But as adoption rises and competition heats up, the race for secure, scalable, and reliable stablecoins is just getting started.
If you’re holding or building on any stablecoin, it’s worth knowing who’s putting in the work to keep those $1 pegs actually worth $1.
