Stablecoins vs. Altcoins: The Battle for Dominance in US, EU, and UK Investment Portfolios

Crypto portfolios are splitting at the seams—stablecoins and altcoins are locked in a tug-of-war across Western markets.

The Safe Haven Play

Tether and USDC keep gaining ground as investors park cash in crypto’s answer to money market funds—zero yield, but hey, at least it’s not your bank’s collapsing balance sheet.

Altcoins’ High-Risk Gambit

Ethereum, Solana, and the usual suspects still lure speculators with promises of 100x returns. Most crash. A few moon. Everyone pretends they saw it coming.

Regulatory Roulette

The EU’s MiCA framework gives stablecoins a fighting chance while the SEC keeps altcoin teams on perpetual subpoena watch. London? Too busy debating whether crypto is ‘real finance’ to notice.

One thing’s clear: portfolios are hedging bets. Stablecoins for the faint-hearted, altcoins for the degens—and the suits still can’t decide which scares them more.

The world of crypto isn’t one-size-fits-all. Regardless of where you’re based – the US, Europe, or the UK – your portfolio reflects more than just personal preference. It’s also shaped by regulation, market sentiment, and the delicate balance of safety and potential gains.

Stablecoins

Stablecoins are having a moment. Backed by fiat currencies like the US dollar or euro, they’re designed to hold steady even when the rest of the crypto market doesn’t. And they are immensely popular. In mid-2025, the stablecoin market in the US had reached $247 billion. That’s roughly 10% of the total US cash supply.

Tether (USDT) and USDC are leading the pack, which hold about 86% of the market. Tether alone holds over $98.5 billion in US Treasuries, making it a real player in traditional finance.

So, what do stablecoins offer investors?

• A safer way to stay in the crypto game without all the volatility
• A profitable way to earn passive income through interest
• Quick exits and entries between trades
• More clarity in Europe, thanks to full MiCA regulation since late 2024

Altcoins

Altcoins, meaning any crypto that’s not Bitcoin or Ethereum, are the wildcard in your portfolio. Think Solana, Cardano, Avalanche, and a few thousand others. Some have serious innovation behind them, and others, not so much. So, it’s essential to do your research.

In early 2025, altcoins saw a resurgence, with the majority outperforming bitcoin in the first quarter. This wasn’t just luck. Investors sought undervalued opportunities and new use cases like tokenized real-world assets.

But make no mistake: altcoins can be volatile. A hot token today might crash tomorrow. That’s why most advisors suggest keeping altcoin exposure limited unless you’re ready to stomach the swings.

Portfolio Allocation Strategies

So, how do most savvy investors build a crypto portfolio? The current trend looks like this:

• 60% core assets like Bitcoin and Ethereum
• 30% altcoins for growth potential
• 10% stablecoins to stay liquid and ready

In Western Europe, the stablecoin share is often higher. In fact, small transactions under $1 million in the EU were more than 52% stablecoin-based in mid‑2024.

Regional Breakdown

Where you invest affects how you invest. Even though crypto is borderless, geography affects access, regulation, and portfolio strategy. Stablecoins and altcoins play different roles depending on local laws, institutional appetite, and infrastructure. Let’s look at how these differences show up on the ground.

United States

In the US, the crypto space is growing fast, but regulation is still catching up. Lawmakers have been working on the GENIUS Act, which lays the foundation for clear stablecoin rules. While not yet law, it’s a step toward giving issuers and investors more certainty.

While lawmakers debate stablecoin legislation, institutions aren’t waiting. A majority of asset managers now plan to increase crypto exposure. The 2025 Institutional Investor
Digital Assets Survey by Coinbase and EY-Parthenon showed that 59% of US asset managers plan to allocate at least 5% of their portfolios to crypto this year. Altcoins remain attractive for growth, but stablecoins are becoming the default for liquidity and trade execution.

European Union

The EU leads in crypto regulation. MiCA (Markets in Crypto-Assets) is fully in effect as of December 2024. This law sets the rules for stablecoin reserves, transparency, and how these digital assets can be used on a crypto trading platform.

European investors lean heavily on stablecoins, especially in countries like France and Germany. Over €422 billion in crypto inflows were stablecoin-based, particularly for smaller retail trades.

While altcoins have grown in popularity, especially during the 2024–2025 bull run, they’re often considered speculative in Europe, used more cautiously, and in smaller doses.

United Kingdom

Post-Brexit, the UK is working on its own crypto rules. The government wants to be competitive but also cautious. Stablecoins are a big part of this, and new legislation is expected to roll out by early 2026.

UK-based platforms like Revolut are moving quickly. Revolut announced plans to issue its own stablecoin, joining the likes of PayPal and other fintech giants in the race.

UK investors use stablecoins for cross-border payments and earning yield like their EU counterparts. Altcoins remain on the menu, but they’re not the main dish.

Key Stats at a Glance

Practical Advice for Investors

Here’s how to build a balanced crypto portfolio in 2025:

• Use stablecoins as your cash reserve. They’re fast, flexible, and, in some cases, they earn you interest.
• Diversify with core assets and altcoins, but don’t go all-in on anything too fast.
• Know your region’s rules. In the EU and UK, compliance matters. In the US, regulations are still shifting.
• Watch the Treasury market because stablecoin issuers are having real-world effects now.
• Stay flexible. If the market turns, you’ll want to pivot. Stablecoins help you do that.

Bringing Balance to Your Crypto Strategy

In the volatile world of crypto, stablecoins offer a welcome sense of calm. Yes, they may not deliver the same results as altcoins, but they’re reliable. Altcoins, on the other hand, are a high-risk, high-reward option.

It’s not about choosing one or the other. It’s about finding the mix that fits your goals, risk appetite, and region. Stablecoins help you stay ready. Altcoins help you aim higher. The smart MOVE is learning to use both, just not equally and not mindlessly.