Solid is a stablecoin app with a non-custodial wallet, DeFi savings, and a virtual Visa card. USDC or USDT arrives in a Wallet first. Moving that balance into Savings converts it to soUSD, a yield-bearing token. The card and any US bank-partner balance sit apart from that vault.
Solid states that it is a financial technology company, not a bank. Savings yield is variable.
What Solid is structurally
Solid is structured as a non-custodial wallet, an onchain savings vault, and a partner-issued card. It does not hold Savings on its own balance sheet.
Solid’s architecture article, dated 20 June 2026, describes ERC-4626 vaults, Safe smart accounts, MPC key management, and gasless transactions through a paymaster. The product site says the user holds the keys, secured with passkeys. It also says Solid cannot move the funds alone. The architecture article says no single party can unilaterally move user funds.
soUSD is an ERC-4626-style token for Savings. The value of each soUSD rises as vault yield accrues. A deposit can show fewer soUSD tokens than the USDC or USDT sent in. A help article dated 20 November 2025 says Savings are allocated through BoringVaults into onchain strategies, including lending markets. Ordinary Savings have no lockup. A separate FUSE lock, used for Rewards tiers, does.
Solid’s disclosures, dated 24 August 2026, name the company as Solid Superapp LLC. Banking services are provided by SSB, Member FDIC. Funds on deposit at SSB can qualify for pass-through FDIC insurance. The cap is $250,000 per depositor, per insured bank, for each ownership category, and only if pass-through recordkeeping rules are met. That coverage protects against SSB’s failure. It does not cover soUSD, yield, or borrowing. It does not protect against Solid’s failure.
The yield token and the bank-partner balance are different products with different loss modes.
How it works in practice
A transfer lands in the Wallet. The user moves funds from the Wallet into Savings to mint soUSD. Yield then accrues in the token’s price. Solid’s fee page says the user can withdraw Savings, subject to a solver fee described below.
Yield Generation and Compounding
Yield comes from curated DeFi strategies, not from a bank deposit rate. The architecture article names lending markets, liquid yield vaults, and stablecoin strategies. It also names smart contract risk, strategy risk, and liquidity risk. On 15 October 2026 the product site displayed “up to 6% APY” on dollars, plus higher headline figures for FUSE and ETH. Solid Rewards Terms, last updated 8 October 2026, say vault yield is variable. An “up to” figure is a maximum, not a promise of a specific return.
Solid keeps a performance fee equal to 10% of yield earned. On $100 of yield, the fee overview’s example leaves $90 in the account and $10 with Solid. The fee is taken from yield, not from principal. The fee overview does not say whether a published APY figure is before or after that 10%.
Prime and Ultra add a Yield Boost above base vault yield. Prime adds 2% APY on the first $10,000 of combined Savings. Ultra adds 3% APY on the first $25,000. The boost accrues daily, is claimed in the app, and is paid in soFUSE. The rewards terms describe that boost as variable.
The Solid Visa Card
The Solid Card is a free virtual Visa card. The card article, updated 15 October 2026, says identity verification in the app activates it. There is no issuance fee. Apple Pay and Google Pay are supported at a $0 fee on the fee schedule.
Cash mode is the default. Purchases pay from the card’s Spendable balance. Wallet and Savings balances are not available to the card until the user moves funds onto it. Credit mode is labeled an early beta and is limited to cards issued by Wirex. In that mode each purchase is a loan backed by soUSD. Savings can keep earning while the card spends. A mode Solid calls Smart is marked as not available yet.
Rain or Wirex issues the card, based on country of residence. The August 2026 disclosures still call it a Visa credit card issued by Rain. Those disclosures put savings, yield, and borrowing on the DeFi protocol, not the issuer. The October 2026 help pages name both Rain and Wirex. They describe Cash mode as working like a debit card.
Non-USD purchases include a 1.5% FX cost in the exchange rate, at every Rewards tier. The card provider’s share is 1%. Solid’s share is 0.5%. Nothing is charged as a second line after settlement. A purchase charged in USD has no Solid FX fee, including at a merchant outside the United States. A euro purchase has no FX fee in two Wirex cases. One is a EUR balance funded with EURC on Base. The other is soUSD with Credit mode on. The euro funding has to cover the whole purchase. A shortfall sends the entire purchase to the dollar balance.
Eligible purchases earn cashback in USDC. Core earns 3%, Prime 4%, and Ultra 5%. Monthly caps are $50, $100, and $200. The card article says the credit posts about 14 days after the transaction settles. Prime category rates are 10% on AI, streaming, and music, and 8% on rides. Ultra rates are 20% on AI, streaming, and music, 10% on rides, and 10% on eligible airlines. Category cashback still counts toward the monthly cap. Cash mode spends the card balance after a transfer. Savings keep earning through a purchase only in Wirex Credit mode.
Fees and pricing mechanics
As of 15 October 2026, Solid’s fee overview prices deposits, swaps, card FX, and yield by Rewards tier. Every member starts at Core. Prime is a $199 annual subscription, or a 12-month FUSE lock. Ultra is a 12-month FUSE lock only. The subscription renews each year from the Solid balance. Renewal stops if the member turns it off before the renewal date. It also stops if the balance cannot cover the charge.
The fee overview lists 50,000 FUSE for Prime and 400,000 FUSE for Ultra. The rewards terms set higher amounts for new locks. From 12 October 2026 at 00:00 UTC, Prime requires 70,000 FUSE and Ultra requires 600,000 FUSE. A lock made earlier keeps its original amount for that 12-month period. Locked FUSE still earns vault yield and cannot be withdrawn, transferred, swapped, or spent until unlock.
| Item | Core | Prime | Ultra |
|---|---|---|---|
| Virtual card, monthly fee, and top-up | Free | Free | Free |
| USD card spend | No Solid fee | No Solid fee | No Solid fee |
| Non-USD FX cost in the rate | 1.5% | 1.5% | 1.5% |
| Bank deposit | 0.5% | 0.25% | Free |
| Swaps | 0.5% | 0.25% | Free |
| Bank withdrawal | No Solid fee today | No Solid fee today | No Solid fee today |
| Savings performance fee | 10% of yield | 10% of yield | 10% of yield |
| Savings withdrawal solver fee | 0.01% | 0.01% | 0.01% |
Crypto deposits are free on Fuse, 0.1% on Ethereum, and 0.03% when bridged from other listed networks. A $100 Ethereum deposit therefore costs $0.10 before any fee charged by the sending wallet. The minimum deposit shown on the fee page is $10. Solid says it covers gas on eligible deposits. A withdrawal from Savings still pays the 0.01% solver fee. The fee page says that charge covers onchain execution.
Opening a US virtual account for ACH and wires costs $10 once. That account is the product’s stablecoin banking rail. If verification for a Rain-issued card is already done, the $10 is not charged again. Third-party bank deposits are capped at $4,000 per transfer. First-party bank deposits are listed without that cap.
Buying USDC with local currency runs through TransFi. The quote includes Solid’s 0.5% fee plus TransFi’s own fee. The fee page’s SEPA Instant example is about 0.65% combined.
The fee overview says a future bank-withdrawal fee of 0.5% at Core, 0.25% at Prime, and free at Ultra is planned. It also says that fee is not charged yet and will be announced in the app before it applies. Crypto withdrawals to an external wallet have no Solid fee. The destination network may still charge its own fee. In-app quotes can still differ by network, partner, and tier.
Limits, eligibility, and availability
Savings can be opened worldwide. The Visa card and virtual accounts cannot. Solid’s card availability article says the card is offered in 105 countries. That list includes the United Kingdom, EU and EEA member states, and the United States in more than 30 states.
The same article blocks issuance for residents of Belarus, China, Cuba, India, Iran, Iraq, Myanmar, Nepal, Nicaragua, North Korea, Russia, Syria, and Venezuela. Use is also blocked in some places even after issuance. Those places are Cuba, Iran, North Korea, Russia, Syria, Venezuela, and the Crimea, Donetsk, and Luhansk regions of Ukraine.
Ordering the card requires identity verification. The card article describes that check as about two minutes in the app, followed by activation. Residents of a country marked unsupported can join a waitlist. They can still open Savings.
Spend limits follow the Spendable balance or collateral. Solid can set them per transaction, day, week, month, year, or lifetime. Those limits can change per user. Transactions above about $250,000 may require extra checks from Visa. The stated single-transaction maximum is about $750,000. A card deposit under $10 is credited to the Wallet instead of the card.
Restricted merchant categories include gambling and unregulated financial services. Cashback exclusions also cover ATM and cash-like transactions, person-to-person transfers, crypto purchases, and financial services.
Country, balance, and merchant rules can stop a payment even when the Wallet shows a larger total.
Tradeoffs, risks, or limitations
The main limit is DeFi strategy risk, plus a 10% cut of whatever yield those strategies produce. The architecture article says the protocol does not promise profits or return of principal. FDIC pass-through coverage, when it applies, stops at funds on deposit at SSB.
Self-custody is the other limit. Solid’s materials say the user holds the keys. They also say Solid cannot unilaterally move the funds. The architecture article does not describe a bank-style reset of those keys.
Default card spending does not keep Savings on yield through the purchase. That path needs a transfer onto the Spendable balance, or Wirex Credit mode. Solid marks Credit mode as an early beta. Cashback is capped each month and skipped on excluded merchants. A 1.5% FX cost is not always offset by the posted cashback rate.
Solid’s own pages do not all state the same lock size or card issuer. The fee overview updated 15 October 2026 still prints the earlier FUSE amounts. The rewards terms state the higher amounts for locks from 12 October 2026. The August disclosures name Rain alone. The October card article names Rain or Wirex.
