Jupiter vs KAST

On paper Jupiter's 4% dwarfs KAST's 1.5%, and for ordinary spending that gap holds.

Up to $2,500 a month, Jupiter pays the full 4% and KAST cannot catch it, because KAST's free rate is lower and its own cap sits at $2,000 of spend (about $30 a month). Jupiter's cashback is also more useful when you get it: rewards settle as USDC you can withdraw to your balance or wallet, while KAST's are locked to your next card purchase.

The turn comes at the cashback cap. Jupiter's $100 a month is a hard ceiling on the base card, hit at $2,500 of spend, so a $5,000 spender still earns $100 and their effective rate has fallen to 2%. KAST's free card does not pay more there either, but its paid tiers do, which is the next section.

KAST is built to keep rewarding past the point where Jupiter's base card stops.

The X Card (Premium, $1,000 a year) pays 2% on the first $10,000 of monthly spend, and Solana Gold (Luxe, $10,000 a year) pays 3% to $50,000. Those are expensive memberships, so they only make sense at high volume, but they raise the ceiling far above Jupiter's $100 a month. A $10,000-a-month spender earns about $1,400 a year net on KAST Premium (2% minus the $1,000 fee) versus Jupiter's capped $1,200, and the gap widens from there. Below roughly $9,000 a month, Jupiter's free 4% still wins.

Foreign spend is the other KAST lever. KAST charges 0% on USD and as little as 0.5% on other currencies; Jupiter charges 1% on Rain-issued cards and 1.8% on DCS-issued ones, and you do not pick the issuer. For a traveler who is also over the cap, KAST's lower FX compounds the advantage. Below the cap, Jupiter's higher cashback usually still absorbs its higher FX, so the FX edge mainly bites for heavier or cap-bound spenders. If FX is your first concern, KAST sits on a no-FX-fee shortlist and Jupiter does not.

Two practical differences decide a lot of cases before cashback even enters.

Availability: KAST serves 170-plus countries; Jupiter Global is live in about 52, concentrated in the Americas, parts of Asia, and a handful of other markets. If Jupiter does not operate where you live, the comparison is settled, and KAST is one of the widest stablecoin cards available.

Format: KAST issues physical cards across its lineup, including chromoly and 24K gold-plated metal, alongside instant virtual cards. Jupiter is virtual-only today; a physical card has been discussed but has no confirmed launch. If you need to tap a physical card at a terminal or pull cash, KAST is the only one of the two that does it now. Both support Apple Pay and Google Pay for in-store use of the virtual card.

Both are stablecoin cards, but the funding and custody mechanics differ.

Jupiter funds from USDC on Solana, credited 1:1 to a USD balance, on a hybrid custody model inside the Jupiter app. KAST takes USDC, USDT, or USDe, converts stablecoins 1:1 at a 0% spread, and runs a custodial model where KAST holds your spending balance. Neither is self-custodial in the way an on-chain wallet card is, so if keeping your own keys is the priority, look at a dedicated self-custody card instead.

The reward fine print is where KAST is weakest. Its cashback is stable USD value, but it is timelocked 14 days, must be manually redeemed, and is then spent on your next purchase only, with no withdrawal to fiat or wallet. Jupiter's cashback is withdrawable USDC. For liquidity of rewards, Jupiter is clearly ahead; KAST's edge is reach, FX, and scale, not flexibility.

Reading Jupiter's "up to 10%" as the rate. The 5%, 8%, and 10% tiers require referring 20, 50, and 100 people, so they are an affiliate mechanic, not a spending rate. How to avoid it: budget Jupiter as a 4% card. If you would not realistically refer dozens of users, the base rate is the number that matters.

Ignoring Jupiter's $100 monthly cap. The 4% only runs to $2,500 of spend; above it you still earn $100 and the effective rate slides toward 2% and lower. How to avoid it: if you spend well over $2,500 a month, price KAST's paid tiers or another uncapped card against Jupiter's flat $100, because past the cap Jupiter stops scaling.

Buying a KAST paid tier for a rate Jupiter already beats. KAST Premium's 2% needs heavy spend just to clear its $1,000 fee, and below roughly $9,000 a month Jupiter's free 4% returns more. How to avoid it: only pay for KAST Premium or Luxe if your volume clearly exceeds Jupiter's cap or you specifically need the metal card and low FX; otherwise the free cards decide it.

Pick Jupiter if you spend up to about $2,500 a month, want the highest free-card cashback with withdrawable rewards and a $100 signup bonus, and you live in a supported country. It is the better starter and mid-tier card on raw return.

Pick KAST if you spend heavily, spend a lot in foreign currency, want a physical or metal card, or live outside Jupiter's roughly 52 markets. Its lower FX and scaling tiers reward exactly the spending Jupiter's cap cuts off.

Use both if it fits: Jupiter as the free 4% card under the cap, KAST for travel, large purchases, and everywhere Jupiter has not reached.

Outlook: Both are young cards still moving fast. If Jupiter lifted or widened its $100 cap, or shipped the discussed physical card, it would close most of KAST's remaining advantages; if KAST raised its free rate or let users withdraw cashback, it would blunt Jupiter's. For now the split is clean: Jupiter for the higher free rate under the cap, KAST for reach, low FX, and spending that runs past where Jupiter stops paying.