How to read on-chain flows: stablecoin mints, exchange netflow, whales and ETF flows

What counts as a flow

A public blockchain such as Bitcoin or Ethereum records every transfer in a ledger anyone can read. The Bitcoin white paper proposed that transactions be publicly announced so that participants can agree on a single history of them. A flow is simply a sum of those transfers over a period, grouped by who sent and who received them.

The grouping is the hard part. The chain shows addresses, not names. Analytics firms label addresses as belonging to an exchange, a fund custodian, a stablecoin issuer or a large holder by tracing patterns of activity, and those labels are estimates that differ between providers. Almost every flow number you see therefore combines a hard fact (these coins moved) with a softer one (who we think owns these addresses).

ETF flows are different again. They are not read from the chain at all; they come from the funds themselves. We cover them separately below. If on-chain data in general is new to you, start with what on-chain data is and come back.

Stablecoin mint and burn

Fiat-backed stablecoins such as USDT and USDC are created (minted) when the issuer receives dollars or equivalent assets, and destroyed (burned) when tokens are redeemed for dollars. A Federal Reserve FEDS Note on stablecoin markets describes this as the primary market, and notes that fiat-backed issuers tend to mint and burn directly only with institutional customers; most people get stablecoins on secondary markets such as exchanges.

On token standards like ERC-20 on Ethereum, the standard says a contract that creates new tokens should emit a transfer event from the zero address, which is why block explorers show a mint as a transfer from 0x000…0. Burns typically show the reverse, or a transfer to an issuer address followed by destruction.

Issuers publish supply and reserve information on their own transparency pages, and supply can also be read directly from each chain. Total supply is the sum across every chain the stablecoin is issued on.

• Hypothetical example: a stablecoin's supply on one chain rises from 100.0 billion to 101.5 billion tokens over a week. That is a net mint of 1.5 billion, or 1.5% in a week.
• The same week, its supply on another chain falls by 1.0 billion. Across both chains the net change is +0.5 billion, a much smaller number than the single-chain headline suggested.

How to read it: rising stablecoin supply describes more dollars entering the stablecoin system, which some analysts treat as more cash available inside crypto markets. It does not say those dollars will buy anything. Minted tokens can sit in an issuer's treasury, move between chains, or be used for payments that have nothing to do with trading. Large mints are often an issuer filling institutional orders, not a bet on direction. For the risks of holding stablecoins themselves, see stablecoin risks.

Exchange netflow

Exchange netflow is the amount of a coin sent to addresses labeled as exchanges minus the amount sent from them, over a period. Positive netflow means more arrived than left; negative means more left than arrived. Many dashboards also show exchange balance, the running total of coins held at labeled exchange addresses.

The usual interpretation is that coins sent to an exchange are more likely to be sold soon, and coins withdrawn to private wallets are more likely to be held. That is a reasonable starting assumption and nothing more. Deposits are also used as collateral for derivatives, moved between an exchange's own wallets, or sent by market makers rebalancing inventory.

• Hypothetical example: over one day, 12,000 BTC are sent to labeled exchange addresses and 15,500 BTC are withdrawn. Netflow is 12,000 − 15,500 = −3,500 BTC, a net outflow.
• If 3,000 BTC of those withdrawals were one exchange moving coins to a newly labeled cold wallet that the provider has not yet tagged, the true net outflow to outside holders would be closer to 500 BTC.

How to read it: compare netflow with its own history in the same data source, look at the trend over weeks rather than one day, and check whether a single large transaction dominates the number. Exchange-balance charts can jump when a provider adds or removes labels, which shows up as a sudden step rather than a gradual change.

Whale transfers

Alert accounts and dashboards often post every transfer above a size threshold, such as transfers worth more than a certain dollar amount. The transfer itself is a fact. The story attached to it usually is not.

Most large transfers are routine: exchanges moving funds between hot and cold wallets, custodians reorganizing client holdings, over-the-counter desks settling trades, or a single owner consolidating addresses. A transfer from an unknown wallet to an unknown wallet tells you almost nothing about intent. A transfer from an unknown wallet to an exchange deposit address is more informative, but it still is not a sale until something is sold, and the chain cannot show that part because exchange order books are off-chain.

• Check both ends: is the sender or receiver labeled, and by whom?
• Check the history: has this address made similar transfers before, for example every month?
• Check the follow-up: did the coins move on from the deposit address, and did exchange balances change?

Spot bitcoin ETF flows

The SEC approved the listing and trading of a number of spot bitcoin exchange-traded products on 10 January 2024. These funds hold bitcoin through a custodian and issue or redeem shares in large blocks with authorized participants, the large financial firms that deal directly with the fund. When demand for shares rises, new shares are created; when it falls, shares are redeemed.

A daily flow figure is essentially the change in shares outstanding multiplied by the fund's net asset value per share. Issuers publish holdings and shares outstanding on their own websites, usually after the U.S. market close, and data providers add up the funds into a single daily total. Because publication schedules differ, early totals can be revised once every issuer has reported.

• Hypothetical example: a fund's shares outstanding rise by 2,000,000 in a day and its net asset value is $40 per share. The day's net creation is about 2,000,000 × $40 = $80 million.
• If the bitcoin price were $80,000, that would correspond to about 1,000 BTC the fund needs to hold for the new shares, although the actual purchase and the custodian's on-chain movements may happen on a different day.

How to read it: ETF flows measure demand for fund shares from investors who use brokerage accounts, which is a different group from on-chain holders. Inflows and outflows are reported in dollars, so a day with rising prices and flat demand can look different from a day with falling prices and the same demand. Compare flows with the size of the funds' total holdings, not just with yesterday's number.

Putting the four together

Each flow describes a different part of the market: stablecoins describe dollars entering or leaving the crypto system, exchange netflow describes coins moving towards or away from trading venues, whale transfers describe individual large movements, and ETF flows describe demand from traditional brokerage investors. They often disagree, and that is normal.

A practical habit is to write one neutral sentence for each, for example: stablecoin supply up slightly this week, exchange balances flat, two large transfers into exchanges from labeled funds, ETF flows negative for three days. That description is useful context for a plan you already have. It is not a reason on its own to buy or sell anything.

Common mistakes

• Treating one large transaction as a signal. Most large transfers are internal movements.
• Comparing flow numbers across data providers. Address labels and methods differ, so totals differ.
• Reading a mint as buying. New stablecoins are supply, not demand for any particular asset.
• Ignoring units. ETF flows are in dollars; exchange netflow is usually in coins. Price changes alone can move dollar figures.
• Reacting to the first ETF total of the day. Late-reporting issuers can change the total after the first headlines.

Sources and further reading

• Federal Reserve FEDS Notes: Primary and Secondary Markets for Stablecoins (2024)
• SEC: Statement on the approval of spot bitcoin exchange-traded products (10 January 2024)
• Ethereum Improvement Proposal 20: Token Standard
• Tether: Transparency
• Circle: Transparency and stability
• Satoshi Nakamoto: Bitcoin, A Peer-to-Peer Electronic Cash System