Build it one stone at a time.
Pick a stock, an amount and how often. Cairn buys it for you on schedule — $25 of NVIDIA every Friday, say — and every share lands straight in your own wallet.
Plan a cairn
Live pricesStock
Each buy
How often
For how long
How it works
Approve, plan, forget
Two transactions from your wallet to start. After that each buy happens on its own day, and you can stop whenever you like.
Approve a budget
You let the Cairn contract spend up to the plan's total in USDG — say 12 × $25. The dollars stay in your wallet; the contract takes each $25 only on the day it buys.
Write the plan
Which stock, how much, how often, how many times, and how far below Robinhood's price you will accept. It is stored on chain, in your name.
Buys run on the day
When a buy is due, anyone can press the button and earn the few cents of tip you set. The shares go to you, never to them. You can press it yourself too.
What keeps it safe
A stranger can press the button. That's fine.
Everything a buy is allowed to do is fixed by you in advance and checked by the contract, every time.
Your money
Nothing sits in Cairn
Cairn holds an allowance, not a balance. It pulls one buy's dollars at the moment of the buy and the shares go straight to you in the same transaction. Revoke the allowance in your wallet and every plan stops.
The price
A floor from Robinhood's feed
Before each buy the contract reads Robinhood's own price feed for that stock and refuses to fill below the slippage you chose. A feed older than four days — a market that has been shut too long — stops every buy.
The schedule
Never early, never in a burst
A buy cannot run before its day, and cannot run twice in one period. Miss a few weeks and the next buy restarts the schedule instead of catching up all at once.
The contract
No owner, no fee, no upgrade
One small contract. Nobody can pause it, change it or take a cut. Only you can stop your plan. It has not been audited: read it on the docs page before you trust it with a large plan.
What you can plan
26 stocks, each with a feed
Only stocks Robinhood publishes a price feed for can have a plan: the feed is what protects each buy. Costs are what a real $25 buy returned through the pool at block 71,637,930, against that feed.
| Stock | Price | $25 buy costs |
|---|---|---|
SGOV Treasury bills ETF SGOV | $101.14 | under |
GME GameStop GME | $25.02 | under |
CRCL Circle CRCL | $93.29 | under |
QQQ Nasdaq-100 ETF QQQ | $741.78 | under |
AAPL Apple AAPL | $336.31 | 0.03% |
AMZN Amazon AMZN | $250.04 | 0.09% |
AMD AMD AMD | $629.89 | 0.11% |
META Meta META | $778.25 | 0.11% |
SPCX SpaceX SPCX | $147.89 | 0.12% |
MU Micron MU | $1079.61 | 0.12% |
NVDA NVIDIA NVDA | $224.41 | 0.13% |
USAR USA Rare Earth USAR | $15.43 | 0.13% |
TSLA Tesla TSLA | $378.34 | 0.13% |
MSFT Microsoft MSFT | $497.99 | 0.17% |
SPY S&P 500 ETF SPY | $766.70 | 0.20% |
INTC Intel INTC | $127.08 | 0.22% |
PLTR Palantir PLTR | $192.51 | 0.22% |
ASML ASML ASML | $1725.68 | 0.22% |
GOOGL Alphabet GOOGL | $341.92 | 0.26% |
GLD Gold ETF GLD | $390.91 | 0.26% |
TSM TSMC TSM | $450.57 | 0.37% |
USO Oil ETF USO | $152.78 | 0.38% |
MSTR Strategy MSTR | $162.22 | 0.45% |
SLV Silver ETF SLV | $57.45 | 0.68% |
SNDK SanDisk SNDK | $1749.88 | 0.68% |
DELL Dell DELL | $538.64 | 1.60% |
Who actually presses "buy" each week?
Anyone. A due buy is a public button: the Due now board lists every plan whose day has come, and whoever runs it earns the tip you set (five cents by default). You can run your own from My plans — then the tip comes back to you. Nothing can make a buy happen early or send the shares anywhere but your wallet.
What if nobody runs it on the day?
Then it runs late, whenever someone does, and the next one is scheduled a full period after that. A buy is never lost and never doubled.
Are these real shares?
They are Robinhood's tokenized stocks on Robinhood Chain: tokens that track the share price, bought from Uniswap's pools. They are not shares held at a brokerage in your name.
What does it cost?
The pool's own fee (0.05% to 1% depending on the stock, shown in the table above), the tip you choose, and your gas to set the plan up — a fraction of a cent on Robinhood Chain. Cairn takes nothing.
What happens at the weekend?
Robinhood's feeds stop printing while markets are shut. Buys still run over a normal weekend — the floor uses the last price — but if a feed goes more than four days without a price, every buy of that stock waits until it prints again.
How do I stop?
Press Stop on the plan in My plans, or simply revoke Cairn's USDG allowance in your wallet. Either one ends every future buy; nothing you already bought is touched.
Start your first stone
A few dollars a week into the companies you believe in. It takes about a minute to set up.