By analyzing the "HODL Structure Chart," we can gain insights into the dynamics of the Bitcoin market. The chart illustrates the relationship between Bitcoin prices (white curve) and various HODL and liquidity indicators from January 2025 to March 2026. The blue curve representing the "Age Concentration Index" is key to this analysis.
In January and February 2025, the Age Concentration Index stabilized between 0.84 and 0.86, while Bitcoin prices fluctuated between $85,000 and $105,000. As mid-year price activity led to a redistribution of tokens across different age groups, the index saw a decline. However, a significant change occurred from late 2025 to early 2026. As Bitcoin prices fell from a high of nearly $125,000 in November 2025 to the current range of about $70,000, the blue Age Concentration Index rebounded significantly, once again approaching 0.84, reaching its highest level since early 2025.
Meanwhile, the "Age Distribution Entropy" index (green curve), which measures the evenness of token distribution across age groups, exhibited the opposite trend. This index declined from mid-term high readings to lower levels at the beginning of 2026, as shown by the downward trend of the green curve on the right side of the chart. When entropy decreases while concentration increases, it indicates that tokens are increasingly concentrated among a smaller group of older holders rather than being actively circulated. This suggests that Bitcoin supply is tightening, with reduced holding and transfer activities.
Coinbase has launched a tokenized Bitcoin fund on the Base chain, even as BlackRock and Fidelity are building similar infrastructures from different angles.
The "Coinbase Premium Chart" reveals another important phenomenon. The second chart tracks the Coinbase premium index from January 5 to March 16, 2026. The green bars represent positive readings, while the red bars indicate negative values. This index measures the difference between Bitcoin prices on Coinbase and those on other global exchanges. Positive values indicate that U.S. buyers are willing to pay above the global average price, while negative values suggest they are paying below it.
From early January to mid-February, the chart predominantly features deep red bars. Around February 4, the most extreme negative reading occurred, with a premium of about -0.225, marking the lowest point on the chart. This reading coincided with Bitcoin prices nearing $73,000, after which the price fell to $62,000 and hit a cycle low of nearly $60,000 on February 7.
The structural shift began in the latter half of February. The red bars narrowed from the extreme negative region, approaching levels between -0.025 and -0.050. From late February to early March, green positive bars appeared for the first time since early January. These green bars continued until March 9 to 16, with several readings exceeding +0.025. The latest readings on the right side of the chart show that the premium has returned to a slight negative value close to -0.016, as indicated by the red label on the left.
The narrowing premium carries significant analytical implications, suggesting that demand for Bitcoin in the U.S. market is relatively weakening, or that buying pressure in the global market has increased, aligning with the trend of tightening Bitcoin supply.