Between April and June 2026 we built Volta, a subscription platform for creators, and shipped three payment rails into it: cards through Stripe, Telegram Stars, and crypto through NOWPayments. Pricing a $10 product on cards or Stars is one decision, made once, at checkout time. Pricing the same product in crypto is two decisions, made at two different moments, and the platform lets you choose whether those moments are the same one.
Most sellers never notice there were two. The invoice looks like a single price. The mechanism behind it is not.
What "the price" means on each rail
A card charge is authorized against a fixed amount in the currency you set. Whatever currency conversion the buyer's own bank does on their end is invisible to you and does not touch what you're owed - you priced the product at $10, Stripe processes $10 minus its cut, and that number does not move after the charge succeeds.[1]
A Telegram Star has no market at all behind it. Telegram fixes what a Star is worth to you in its own terms, "at its discretion," and that figure can change over time based on Telegram's own read of the market - not a live exchange, just a number Telegram publishes and can revise.[2] We covered what that number is and what it does to your effective price in the first article we wrote about this. Reprice risk on Stars is policy risk. Nobody is trading anything.
Crypto is the only one of the three priced against an actual live market, and NOWPayments gives you two different relationships to that market for the same sale.
Floating by default
Create an invoice and NOWPayments shows the buyer a coin amount, computed from a live rate at that instant. Under the standard flow, that number is a preview, not a lock: the real conversion "happens when the money reaches the processing stage"[3] - after the buyer has found their wallet, entered the amount, and broadcast the transaction, which is however long the buyer takes plus however long the chain takes to move it into a state NOWPayments will act on.
That gap is where the floating rate floats. Whatever the market did to the pair between the quote and the processing moment, that's the rate the sale converts at, not the one the buyer was shown. On a $10 impulse purchase paid within a minute of a liquid pair like USDT, the gap is close to nothing. On a $10 sale in a more volatile coin, paid twenty minutes after the buyer got distracted and came back to it, it is a real number, and it can move in either direction. You are not protected from the downside, and you don't get to keep the upside either without deciding to.
Put a rough number on it. Price a $50 course in a coin with ordinary day-to-day volatility, and a buyer who takes fifteen quiet minutes to complete the payment exposes that sale to whatever the pair did in that window - most likely a swing of a few tens of cents, either way, on an ordinary day. The same fifteen minutes during a news cycle on that same token could move it by several dollars, with neither side doing anything unusual. NOWPayments isn't warning you about a slow buyer. It's telling you the invoice number was never a promise to begin with.
What the fixed-rate option actually freezes
NOWPayments sells the fix to this, and the fix is specific rather than general. Turn on the fixed-rate flow and the quote is frozen the moment it's generated. The buyer then has a strict two minutes to start the payment and ten minutes total to get the deposit sent.[3] Miss that window and the transaction is either refunded or falls through to the ordinary floating rate at whatever the market is doing by then.[3]
Ten minutes is not a formality. It is the entire size of the promise. NOWPayments is underwriting ten minutes of price movement for you, once, per invoice. It says nothing about the ten minutes after that if the buyer is slow, and nothing about a buyer who reopens an old invoice link the next day - a fixed-rate quote from yesterday is not still fixed.
We never built a UI that told a buyer their price was about to expire. In hindsight, a ten-minute countdown on a fixed-rate checkout is the honest description of what you sold them, and we shipped a flat number instead.
The floating side has no equivalent on cards or Stars
This happens on exactly one of the three rails, and the reason is structural. A card network settles in the currency of the charge, full stop - there's no intermediate asset whose price could move between authorization and settlement. Stars aren't traded against anything, so there's no window for a market to do something in. Crypto is the only rail where the thing the buyer sends and the thing you get valued in are, for a moment, two different assets connected by a live price. Floating rate is the honest default for an asset that has a market; fixed rate is the paid-for exception.
Settled is not the same as spendable
There's a second, separate gap worth naming, because it's easy to fold it into the first one and it isn't the same thing. Once a crypto payment clears, NOWPayments moves it to your wallet about as fast as the chain allows - it's a direct wallet-to-wallet transfer, not something NOWPayments holds and schedules out on its own timetable.[4] That part is genuinely fast, faster than either of the other two rails' first payout.
What lands in your wallet is still crypto. Turning it into currency you can spend on rent is a separate step, on a separate service, with its own rate and its own fee, and nothing in this comparison covers it. Contrast the other two: a card payout is dollars in a bank account by construction, and Stars convert - after their own three-week hold - into TON, another crypto asset, not into dollars either. Of the three rails, cards are the only one where "settled" and "spendable in the form you probably want" are the same event.
What this changes about pricing crypto at all
If you take crypto, decide the floating-versus-fixed choice per price point rather than once for the whole rail. A $4 tip jar doesn't need ten minutes of underwriting - the exposure on a stray 3% market move is twelve cents, smaller than thinking about it. A $200 one-time purchase is a different sale, and locking the rate for the ten minutes it takes a buyer to actually pay is a small, known cost against an unbounded one.
Tell the buyer which one they're getting, too. "Price locked for ten minutes" next to a countdown is a specific, checkable promise. "Price shown in USD equivalent" without that label reads the same on a fixed and a floating invoice, and only one of them is actually true by the time the payment lands.
Fee comparisons across cards, Stars and crypto - including the one we ran on this same $10 sale - measure the wrong risk if crypto is the only rail on the list whose sale price can still move after the buyer has agreed to it. It's a design decision NOWPayments hands you per invoice, not a percentage, and most integrations we've seen never surface it as a choice at all.
Disclosure. Volta was our product, it is retired, and nothing here is a recommendation to use it. The reading of what floating rate exposes you to, and the pricing-by-ticket-size suggestion above, is drawn from our own integration rather than anyone's documentation, so it carries no citation. Everything attributed to NOWPayments, Stripe or Telegram is quoted from public documentation, listed and dated below.