Before you deposit: USDC, ETH and Arbitrum, explained from zero

A wallet is not an account on somebody's server. It is a pair of keys that proves ownership of the tokens or cryptocurrencies recorded on a public ledger, the blockchain. The address (the 0x… string) is the public part: you share it to receive money, like a bank account number. The private key and the 12-word recovery phrase are the secret part: whoever has them controls the money, and there is no password reset, no customer service and no way to reverse a transfer.

The app creates a wallet on your phone and keeps the keys encrypted there. Nothing is held by the developer: the USDC in that wallet is yours, and you can recover it in any other wallet using the same 12 words — even if this app one day stops working.

Rule zero: the 12-word phrase is only typed inside a wallet app, and only at two moments — when importing a wallet you already have into a new app (for example, installing this app on a new phone) or when restoring your wallet into another cryptocurrency wallet app. Never type it on a website, in a chat or on a page opened from a link: nobody legitimate, including this project, will ask for it by message, email or support.

USDC is a stablecoin: a token issued by Circle, a regulated US company, designed to keep its price stable at US$ 1.00. Each unit is backed by cash and short-term US government debt kept in reserve, and the issuer publishes monthly reports on those reserves. It is not a coin that goes up and down: it is a dollar that travels over blockchains.

It is also not a bank deposit. There is no deposit insurance, no interest and no institution to call if you make a mistake: you hold it yourself. In this project, USDC is the money the strategy trades with — the dollar value of your USDC barely moves: the stablecoin is designed to be worth close to one dollar. What rises and falls is the dollar value of the cryptocurrencies you hold (BTC, ETH), not the USDC.

Stablecoin means stable price, not stable outcome: the automation can still lose part or all of the USDC deposited. The stability is about the dollar value of each unit, not about the strategy.

ETH (ether) is the cryptocurrency of the Ethereum blockchain. Arbitrum One is a blockchain built on top of the Ethereum blockchain, so every transaction on Arbitrum One pays its fee in ETH — including a transfer of USDC. That fee is called gas.

A USDC transfer on Arbitrum costs a fraction of a cent, but the network requires a balance of ETH to charge it. About US$ 1 of ETH on Arbitrum One is enough for many transactions; the app warns you when the balance runs out.

ETH is volatile, so do not keep more of it than you need for fees: buy the equivalent of a dollar or two and leave the rest of the money in USDC.

The same token can live on several networks at once. USDC exists on the Ethereum network, Arbitrum, Base, Polygon, Solana and others: same name, same price, different blockchains. They do not talk to each other automatically. USDC sent on the wrong network does not appear in the destination wallet, and getting it back usually requires technical work — sometimes it is simply lost.

Arbitrum One is a layer 2 of the Ethereum network: it settles on the Ethereum network but processes transactions far more cheaply, cents instead of dollars. Its chain ID is 42161. The app, the Hyperliquid bridge and the wallet it creates all work on Arbitrum One.

If your wallet or exchange shows a contract address for USDC, the native one on Arbitrum One is:

0xaf88d065e77c8cC2239327C5EDb3A432268e5831

Some apps also list an older bridged version called USDC.e or “Bridged USDC”, with the same ticker and a different contract. It is a different token: the app will show a zero balance if that is what you send.

Three routes, from the simplest to the most manual. In all of them the goal is the same: USDC and a little ETH, on the Arbitrum One network, at the address the app shows.

1. On-ramp: buy with card or bank transfer

An on-ramp sells crypto directly for local currency and delivers it to an address you provide. You choose the asset (USDC), choose the network (Arbitrum One), paste the address and pay by card, Apple Pay, Google Pay or bank transfer. Fees are usually a percentage plus a spread — compare before confirming — and buy the ETH as a separate, small order.

• MoonPay — card, Apple Pay and Google Pay in many countries; supports Arbitrum.
• Ramp Network — bank transfer and card in Europe and many other countries; sells USDC on Arbitrum.
• Transak — card and local payment methods in a large number of countries; often offered inside wallets.
• Onramper — not a provider itself: it compares several on-ramps in one checkout and lets you pick the cheapest.

Examples, in no particular order. Availability, payment methods, limits and fees depend on your country and change often, so check them at checkout. Listing here is not an endorsement and this project receives nothing from these services.

Minimum purchase: before paying, check whether the provider sells a small amount of ETH — close to 1 USDC. Several require a minimum per order; if the ETH minimum is high, you end up holding a large amount of ETH (which moves up and down) or you have to skip the purchase, because the minimum is incompatible with the fee you simply need to pay.

2. Exchange: buy, then withdraw

A crypto exchange lets you buy USDC with local currency — PIX, bank transfer or card — and then withdraw it to your own address. Buy the USDC, open Withdraw, paste the app address, choose the network Arbitrum One (it may appear as “Arbitrum” or “ARB”) and confirm. Withdraw the ETH the same way: same address, same network. If the withdrawal screen does not offer Arbitrum One for one of the two assets, do not send it on another network — buy somewhere that does.

Large exchanges such as Binance, Coinbase, Kraken, OKX and Bitget offer USDC withdrawals on Arbitrum, and most countries have regional options — Mercado Bitcoin, Bitso and Ripio in Latin America, for example. Availability depends on your country and on your account being verified.

Withdrawal minimum: check the exchange withdrawal minimum for each asset. The USDC you want to use may leave without a problem, but US$ 1 of ETH may sit below the withdrawal minimum — and then the deposit in the app fails for lack of a fee. In that case, withdraw the ETH from an exchange that accepts the small amount, or withdraw a little more ETH than you need.

3. Wallet with a built-in purchase

Some wallets sell crypto inside the app, through an on-ramp partner. It is convenient, but watch the destination network: some flows deliver the USDC on the Ethereum network or Base rather than Arbitrum, and then you need a cross-chain swap before you can deposit. If you use this route, confirm the network on the review screen before paying.

• MetaMask — browser extension and mobile app; holds Arbitrum One assets and has a buy flow with partner providers.
• Trust Wallet — mobile app with in-app purchase and Arbitrum One support.
• Exodus — desktop and mobile; supports Arbitrum One and buys with card or bank transfer.

All three are self-custody wallets: the keys are yours, so the 12 words matter as much as in this app.

Minimum purchase: try buying 1 USDC of ETH first. If the wallet refuses because of the minimum, buy the whole amount you intend to use in the app in ETH and then swap 99% of that ETH, already on Arbitrum One, for USDC on Arbitrum inside the wallet itself. In the end you hold the USDC you want to deposit plus a small remainder of ETH only for fees.

You do not need to buy again. If you already hold USDC in a wallet on the Ethereum network, Polygon, Optimism, Base or another network, you can swap it for USDC on Arbitrum One inside the wallet itself, or in a service that does the cross-chain swap. It works like a bridge: the service takes your USDC on the network you have and delivers USDC on Arbitrum One to your address, usually within minutes.

Before confirming, check two things: the destination is your address, and what arrives is USDC on Arbitrum One — not USDC on the Ethereum network. Compare the fee, usually a percentage of the amount plus the network cost, and send a small amount first. If the wallet only offers swaps between tokens on the same network, use the cross-chain option or withdraw on Arbitrum straight from an exchange.

The app shows the wallet address on the dashboard: the 0x… string you can copy. The idea is the same in both cases, but the screens differ.

1. In the app, copy the wallet address and check that the network shown is Arbitrum One.
2. From another wallet: Send, paste the address, network Arbitrum One, amount, confirm. From an exchange: Withdraw, paste the address, network Arbitrum One, amount, confirm — “withdraw” is simply the name exchanges use for sending to an external wallet.
3. Send a small test first, for example US$ 5 of USDC. Confirm in the app that the balance appeared, then send the rest.
4. USDC arrives in seconds. The wallet also needs ETH on Arbitrum One before you press Deposit in the app, otherwise the transaction reverts for lack of gas.

If you already hold USDC on Hyperliquid, the app has a flow for that case. Deposits made through the app use the correct bridge contract and keep the accounting of deposits and withdrawals consistent.

1. Wrong network: sending USDC on the Ethereum network, BNB Chain, Base or Polygon to an Arbitrum address.
2. The wrong token: USDC.e, the older bridged version, has the same ticker in some apps but is a different contract, and the app will show a zero balance.
3. Typos and clipboard junk: copy the address from the app, do not retype it, and compare the first four and the last four characters.
4. No ETH for gas: the deposit reverts, nothing happens, and it looks like a broken app when it is a missing fee balance.
5. Fake support: nobody from this project will message you first, ask for the 12 words, or ask you to “validate” your wallet on a website.

• USDC on Arbitrum One, native USDC, sent to the address shown in the app.
• Around US$ 1 of ETH on Arbitrum One at the same address.
• Minimum of 5 USDC per deposit; a 2% fee applies to every deposit and comes out of the amount you send.
• The 12 words written on paper, stored offline and never photographed.
• A small test transfer confirmed in the app before sending the full amount.
• Nobody looking at your screen while you copied the address.

If you plan to use the app with more than one wallet, you do not need to buy twice: 0x2ALL has an option to send ETH and to send USDC between wallets on Arbitrum One. Acquire both assets once and distribute them among your wallets with the app itself — these transfers cost nothing beyond the Arbitrum network gas fee.

That is all of it: two assets, one network. If you can copy an address and pick Arbitrum One in a dropdown, you can fund this app — and the 12 words of each wallet inside it are the only thing you must never lose.