The Full Picture of BTC Supply Tightening: Changes in Bitcoin Market Structure Revealed by 8 On-Chain Data Sets

Prices are the manifestation of the market, while supply is the backbone of the market. In Q2 2026, Bitcoin prices maintained wide fluctuations amid the bulls and bears, but on-chain data tells a more convergent story — the supply side of BTC is undergoing a series of structural tightening. These signals are scattered across different indicators and data dimensions; observing any one set alone may lead to a biased conclusion, but when pieced together, a picture of supply contraction is becoming clear.

It is important to emphasize that supply tightening does not equal price increases. It describes a decreasing trend of available BTC in the market, and the ultimate price direction depends on changes on the demand side — including institutional allocation behaviors, macro liquidity, regulatory environment, and other combined factors.

Signal 1: Long-term holder holdings approach historical peak

Long-term holders refer to addresses holding BTC for over 155 days. Their behavior is a core indicator for judging the market’s supply structure. According to Glassnode data, as of May 1, 2026, long-term holders controlled over 73.77% of the BTC supply, approaching the previous cycle’s historical peak range. According to Glassnode’s official definition, BTC that has not moved for 155 days is classified as long-term held, meaning an increase in this proportion directly reflects a growing share of coins in the market that are unwilling to participate in turnover.

This trend has shown acceleration over the past 12 months. In mid-2025, the proportion was about 70%, then steadily increased. In typical market cycles, the proportion of long-term holders peaks during bear market bottoms and significantly declines near market tops — as holders transfer coins to new entrants. The current high proportion, in a relatively high price range, indicates these holders have not chosen to distribute their holdings on a large scale at this price level.

Glassnode’s analysis report on May 5, 2026, also notes that although BTC has surpassed $80,000, profit-taking among long-term holders has not reached the scale of daily sales exceeding $1 billion as seen at cycle peaks. The current daily realized profit is about $180 million, far below peak levels. This restraint itself is a signal of supply tightening.

Signal 2: Exchange BTC balances fall to multi-year lows

Exchange balances are a direct indicator of short-term selling pressure. Rising balances mean more BTC are transferred to exchanges, ready for sale; falling balances indicate BTC are flowing out of exchanges into long-term custody.

According to cross-verified data from CryptoQuant and Glassnode on the Gate platform, as of early May 2026, the total BTC reserves on centralized exchanges worldwide have fallen to about 2.68M coins, the lowest since December 2017. Historically, exchange BTC balances peaked above 3.2 million in 2024, then decreased to about 2.73 million in March 2026, and further declined to approximately 2.68M, a reduction of over 520k coins.

In just the three months from February to May 2026, Binance, OKX, and Gemini together saw nearly 100,000 BTC flow out, worth over $8 billion. Specifically: Binance reserves dropped from about 670,000 BTC to about 620,000 BTC; OKX from about 132,000 BTC to about 102,000 BTC; Gemini from about 114,800 BTC to about 95,000 BTC.

On-chain, the outflow of BTC from exchanges mainly flows into three directions: self-custody cold wallets, spot ETF custody accounts, and long-term holder addresses. Ark Invest’s Q1 2026 Bitcoin quarterly report shows that the supply held by steadfast holders increased sharply from about 2.13 million to 3.6 million BTC, a 69% increase, reaching the highest accumulation level since 2020.

Signal 3: Miner behavior shows structural differentiation

As natural sellers of BTC — needing to sell mining rewards to cover electricity and operational costs — miner behavior changes have a unique impact on supply. On April 20, 2024, BTC’s third halving occurred at block height 840,000, reducing block rewards from 6.25 BTC to 3.125 BTC, and daily miner output from about 900 BTC to about 450 BTC. The absolute reduction in supply is an established fact.

Post-halving, miner behavior is not solely “shifting toward accumulation.” Data from Q1 2026 shows that publicly disclosed miners sold about 32k BTC in that quarter, reflecting some passive selling pressure due to profit compression after the halving. But as weaker miners exit gradually, the sell pressure indicator among remaining miners has dropped significantly from cycle highs to about 5.9, confirming a sharp contraction in short-term miner selling pressure on-chain.

Currently, the mining sector shows clear structural differentiation: large, low-cost, high-efficiency miners tend to hold BTC on their balance sheets and strengthen reserves; high-cost miners are forced to distribute under profit pressure. This differentiation means the overall net selling pressure from miners has been significantly alleviated compared to early stages of reduction. Miner reserves have rebounded to about 1.8 million BTC, with some miners choosing to hold positions at current price levels.

Signal 4: Continuous net inflows into ETFs and custody lock-in effects

Since the approval of the US spot BTC ETF in January 2024, the cumulative net inflow into ETF products has become an important variable in BTC demand. According to Gate’s aggregated data, as of early May 2026, the US spot BTC ETF has accumulated net inflows of about $58–59 billion, with total assets under management (AUM) around $102–103 billion.

The custody structure of ETFs has a special locking effect on BTC supply. The underlying BTC held by professional custodians is not reflected in short-term exchange balance data and does not participate in active on-chain circulation. The total BTC held by US spot Bitcoin ETFs is about 1.32 million, close to 7% of the total circulating supply. As ETF scale increases, the amount of BTC locked in custody also increases, effectively narrowing the truly tradable BTC supply in the market.

Recent inflow momentum shows that April 2026 was the strongest month for US spot Bitcoin ETF net inflows, about $1.97–2.44 billion. On May 1, a single-day net inflow of about $630 million was recorded, led by BlackRock’s IBIT with $284 million. In the first three weeks of May, net inflows totaled about $2.7 billion. Meanwhile, May 7–8 saw two consecutive days with about $415 million net outflows, indicating that institutional flow rhythm is not purely linear, but the overall trend remains upward.

Signal 5: On-chain active supply drops from historical highs

“Active supply” refers to the amount of BTC that has moved on-chain within a recent period, a direct indicator of market liquidity. As of May 8, 2026, Glassnode’s latest data shows that about 59.96% of BTC have not moved in the past year.

Breaking down by holding periods: BTC held over 1 year accounts for about 59.96%; over 2 years about 48.4%; over 3 years about 42.7%.

Notably, this indicator hit a record high of 70.35% in November 2025. The current level of 59.96% has declined from the high, reflecting that some long-term holders have realized profits during the price rebound. But it remains in a relatively high range, above most cycle phases. The process of this indicator retreating from extreme highs to a high level indicates that supply is not monolithic — some long-term holders take profits during price rises, while others continue to hold.

Signal 6: OTC trading share surges, public market liquidity thins

OTC trades, which do not appear on exchange order books, have a significant impact on actual BTC circulation. According to CryptoQuant data, about 92.1% of recent total BTC trading volume has been conducted OTC, with only about 7.9% on public order books. OTC trading share has risen to 82.26%, with Coinbase accounting for 58.21% of the remaining CEX order book trades.

The rise in OTC trading usually indicates that large traders — including institutions, miners, and high-net-worth individuals — prefer off-market channels for buying and selling rather than placing orders on public exchanges. This behavior impacts public market liquidity in two ways: on one hand, large OTC trades do not enter the order book, reducing depth and liquidity on exchanges; on the other hand, OTC counterparties tend to hold for longer periods, not re-entering the market quickly.

Meanwhile, Binance’s OTC data shows that in the first two months of 2026, OTC volume reached 25% of the total OTC volume in all of 2025. The proportion of BTC traded OTC surged from 4.91% in January to 45.81% in February. This trend strongly suggests that large capital is increasingly deploying via OTC channels rather than retail trading on public markets.

The thinning of public market liquidity means smaller buy/sell actions can have a larger impact on prices, and the structural change in market depth itself is an auxiliary signal of supply tightening.

Signal 7: Halving supply shocks deepen

The fourth halving of BTC occurred on April 20, 2024, about 25 months ago. Historically, the core impact of halving on supply does not happen at the event itself but gradually manifests during the 12–24 months afterward as supply and demand rebalance.

Before halving, daily miner output was about 900 BTC; after, it dropped to about 450 BTC. Annually, new BTC supply decreased from approximately 328,500 BTC to about 164,250 BTC, a reduction of roughly 164,250 BTC in annual incremental supply. The annual issuance rate of BTC fell from about 1.7% to about 0.85%.

Assuming demand remains unchanged, this supply halving creates a supply-demand gap. In reality, continuous ETF inflows and accumulation by long-term holders during 2025–2026 further amplify this gap. ETFs are absorbing far more BTC than mined, pushing supply shocks. Corporate buying is 2.8 times the rate of new mined BTC — each newly mined BTC faces institutional demand surpassing its entry into the market. Daily ETF net inflows fluctuate around several hundred million dollars, meaning ETF demand alone can cover or even exceed miners’ daily production.

Signal 8: Stablecoin market cap expansion and purchasing power accumulation

The supply tightening signal is not only about BTC reduction but also about the accumulation of purchasing power. According to Gate’s aggregated data based on DeFiLlama, as of May 10, 2026, the total stablecoin market cap is about $322.74 billion, with USDT leading at about $189.63 billion, holding roughly 58.76% of the market share. The global stablecoin market cap has surpassed $320 billion, with USDT and USDC continuing to dominate.

Stablecoins themselves are not BTC buying actions, but they represent the market’s readily deployable purchasing power reserves. From May 3 to 10, 2026, USDC saw inflows of about $1.61 billion in one week. The overall expansion of the stablecoin market indicates increasing liquidity flowing into crypto ecosystems. Historical data shows that rapid growth in stablecoin circulation often precedes significant BTC price movements. The accelerated month-over-month growth of stablecoin market cap from April to May 2026 provides a window to monitor subsequent demand releases.

Supply tightening does not necessarily mean price will rise

After reviewing these eight signals, it is necessary to take a holistic narrative perspective. Supply tightening describes the objective trend of decreasing tradable chips in the BTC market, and these eight signals from different dimensions collectively point to this trend. However, equating “supply tightening” with “price necessarily rising” is a common logical leap in market narratives.

Demand-side changes are equally critical. Several variables in the current market deserve attention: the global macro liquidity environment — the Federal Reserve’s monetary policy path will directly influence risk asset pricing; the pace of institutional allocation — whether ETF inflows can sustain; and regulatory policy evolution — whether major jurisdictions’ attitudes toward crypto assets shift.

Supply tightening is a fact; demand-side uncertainty is also a fact. On-chain data provides a clear picture of the supply side, not a definitive price direction.

Conclusion

BTC’s supply tightening is not based on a single indicator but a set of cross-dimensional on-chain signals pointing to a common trend. The proportion of long-term holders reaching 73.77%, exchange balances dropping to 520k coins, short-term miner sell-off significantly easing, ETF cumulative holdings of about 1.32 million BTC forming a structural lock-in, OTC share rising above 80% — each signal alone might not attract much attention; but when they resonate within the same time window, the structural tightening of market supply becomes a clear on-chain profile.

These signals do not constitute any directional judgment on price; they merely objectively record the deep changes occurring on the supply side of BTC. On-chain data never lies, but its language must be read in full — not selectively extracted.