Protecting Your Hyperliquid Assets: OneKey Cold Storage Guide

Why cold storage matters (especially for onchain trading)

Hyperliquid has pushed onchain trading UX closer to centralized-exchange speed, but the security model is still crypto-native: you are responsible for your keys, your approvals, and every signature you produce.

In 2025–2026, two trends made “secure-by-default” setups more important than ever:

• Signature phishing and wallet drainers are still active. Even though Scam Sniffer reported 2025 drainer-related losses fell to $83.85M (down 83% YoY), the key point is that attackers keep adapting—and spikes tend to follow market activity (Scam Sniffer 2025 report).
• Social engineering remains extremely effective. The FBI’s Operation Level Up highlights how many victims don’t realize they’re being scammed until it’s too late (FBI overview).

Cold storage won’t prevent every loss category (for example, you can still sign a malicious approval), but it dramatically reduces the blast radius of the most common failures: key theft, device compromise, and “one bad click” wiping your entire portfolio.

Know what you’re protecting: where assets live in this ecosystem

Before building a security plan, map your funds:

HyperCore vs HyperEVM: two environments, two risk profiles

• HyperEVM is live on mainnet with Chain ID 999, and uses an EVM RPC at https://rpc.hyperliquid.xyz/evm (official setup details: How to use the HyperEVM).
• The EVM environment enables smart contract interactions—meaning token approvals, Permit-style signatures, and dapp risk become part of your threat model.

If you only trade perps and keep minimal balances exposed, your risk is different than if you are actively using EVM dapps with broad allowances.

Deposits / withdrawals: USDC on Arbitrum is the operational rail

Key operational constraints users frequently get wrong:

• The official onboarding guide notes you need ETH + USDC on Arbitrum to deposit, and withdrawals charge a $1 fee (onboarding guide).
• Only USDC deposits from Arbitrum are supported. Sending other tokens can lead to loss (support FAQ).

Also note: Arbitrum’s official bridge URL has changed—Arbitrum Portal states the bridge moved from bridge.arbitrum.io to portal.arbitrum.io/bridge (Arbitrum Portal).

The realistic threat model (what actually drains users)

1) Phishing that tricks you into signing, not “hacking the chain”

Modern drainers often rely on getting a valid signature from you. That signature can authorize token movement without “stealing your private key”.

2) Malicious approvals and Permit signatures

EIP-2612 (“permit”) enables approvals via signatures. It’s powerful, but like any approval mechanism it creates an attack surface if users sign messages they don’t fully understand (EIP-2612).

Rule of thumb: treat every approval as “someone can spend my tokens later”.

3) Address poisoning and copy-paste failure

Attackers can “seed” your history with lookalike addresses. If you copy from history, you may send funds to the wrong destination (address poisoning explainer).

4) Fake support, fake bridges, fake “recovery”

If “support” asks you to:

• import a seed phrase
• “sync” a wallet
• share a screen + reveal backups

…it’s a scam. And it scales: the U.S. Department of Justice has pursued large forfeiture actions tied to confidence scams and laundering (DOJ press release, June 18 2025).

The core strategy: split “Trading” from “Vault”

A clean security architecture is simple:

• Vault wallet (cold): long-term holdings, withdrawal destination, never connects to random dapps.
• Trading wallet (hot): small working balance only, used for day-to-day interactions.

This is where a OneKey hardware wallet fits best: keep your Vault keys offline, and treat your Trading wallet as disposable.

OneKey cold storage setup (practical, step-by-step)

Step 0: Prepare a safe environment

• Initialize the device in a private place (no cameras, no screen sharing).
• Don’t store seed backups in cloud notes, email drafts, or photo albums.

Step 1: Create your Vault on OneKey (offline-first)

On your OneKey device:

• Generate a new seed phrase on-device
• Set a strong PIN
• Consider using a passphrase feature if you understand the tradeoff (extra security vs extra complexity)

Store the backup in a way that survives:

• water / fire
• theft
• “future you” forgetting where it is

Step 2: Create a separate Trading wallet

This can be a software wallet on a daily machine, but it should hold only what you’re willing to expose to web risk.

Practical guideline:

• Keep 1–4 weeks of operating capital in the Trading wallet
• Keep everything else in the Vault (OneKey)

Step 3: Fund the Trading wallet correctly (Arbitrum rail)

1. Bridge to Arbitrum using the official Arbitrum Portal bridge: Arbitrum Bridge
2. Ensure you have:
   • USDC on Arbitrum (for deposits)
   • some ETH on Arbitrum (for gas to deposit)

Then follow the platform’s deposit instructions from the official onboarding guide (deposit + withdraw FAQ).

Step 4: Withdraw profits to your OneKey Vault address (not to an exchange deposit address)

When you reduce risk, do it immediately:

• Withdraw USDC to Arbitrum (expect the $1 fee) using the official flow (withdraw steps).
• Use your OneKey-controlled Arbitrum address as the destination.

If you use HyperEVM dapps, periodically move excess funds back to the Vault instead of leaving them exposed to approvals.

“Cold storage” is not enough: add wallet hygiene

Keep approvals under control (the #1 overlooked risk)

Even with a hardware wallet, a bad approval can drain you. Build a routine:

• Avoid unlimited approvals unless necessary
• Revoke approvals you no longer need

A practical tool walkthrough is here: How to revoke token approvals.

Use an address book + test transfers

For any new withdrawal destination:

• Save it as a named contact (don’t copy from history)
• Send a small test transfer first
• Then send the full amount

This directly mitigates address poisoning style mistakes (overview).

Verify HyperEVM network details before interacting

If you add HyperEVM to a wallet app, confirm:

• Chain ID is 999
• RPC matches official docs (network details)

This reduces the risk of signing transactions on a spoofed network configuration.

A minimal, repeatable security checklist

Weekly:
- Sweep profits from Trading wallet to Vault
- Review + revoke unnecessary approvals

Before signing anything:
- Confirm domain and action (approval vs swap vs transfer)
- Never sign “blank” or unclear messages

Before any large withdrawal:
- Use address book (not history)
- Send a small test amount
- Then send the full amount

Closing: when a OneKey device makes the biggest difference

If you’re active onchain, the best security upgrade is usually not a new strategy—it’s isolating your long-term keys from everyday internet risk.

Using a OneKey wallet as your Vault makes that separation easy: your private keys stay on the device, while your Trading wallet remains a controlled-risk workspace. This “Vault vs Trading” split is the most practical way to protect serious balances without giving up the speed that onchain trading is known for.