On May 9, 2025, Bitcoin trades at approximately $103,046, with many market participants anticipating new all-time highs before year-end. Amid this bullish sentiment, analysts are turning to long-standing predictive frameworks to gauge the digital asset's trajectory. Two of the most discussed models — the Stock-to-Flow (S2F) model and the Rainbow Chart — have both flashed signals pointing to explosive growth over the next 18 months, albeit with notable caveats.
Stock-to-Flow Model: Scarcity as the Ultimate Driver
The S2F model quantifies scarcity by comparing the existing supply (stock) to annual new issuance (flow). Bitcoin's quadrennial halving reduces the block reward, thereby cutting the flow and increasing scarcity over time. According to the model, this heightened scarcity should exert upward pressure on price. Currently, the price trajectory is shaded red to orange, indicating that the network is roughly one year past the most recent halving event. Historically, the 12–18 months following a halving have produced the most vigorous rallies. The S2F projection suggests an exponential climb that could land Bitcoin at approximately $275,000 by late 2026. This forecast aligns with the growing institutional adoption seen through ETFs and firms like MicroStrategy (now Strategy) accumulating large reserves. However, the model has faced criticism for not accounting for external shocks — such as geopolitical conflicts, trade policy shifts, or regulatory crackdowns — and for its significant deviation from actual price during the 2022 downturn.
Rainbow Chart: From ‘FOMO’ to ‘Is This a Bubble?’
The Rainbow Chart, created by a Reddit user, plots Bitcoin's price history against logarithmic growth bands that correspond to different market sentiment stages. The current band, labeled ‘FOMO’ (orange), sits just above $100,000. According to the original chart, over the next 18 months, the price is expected to progress into the ‘Is This a Bubble?’ zone, which spans roughly $290,000 to $365,000. The colored bands represent long-term logarithmic growth, implying that if historical patterns hold, Bitcoin will traverse these emotional thresholds before entering more speculative territory. The Rainbow Chart has undergone multiple revisions as more data became available; early versions relied on sparse data and exaggerated growth assumptions, but later adjustments applied better statistical techniques to avoid overfitting. Despite these improvements, critics argue that the Rainbow Chart lacks empirical rigor and remains vulnerable to curve-fitting biases.
Frameworks Illuminate Paths, But Markets Decide Destinations
When taken together, both models suggest that Bitcoin's maturation is approaching another inflection point. Yet as the article originally noted, “mathematics alone cannot capture every catalyst fueling digital asset markets.” Incorporating liquidity shifts, regulatory developments, and investor psychology will likely sharpen any forecast. The colored bands and scarcity ratios are best treated as guideposts rather than ironclad fortune-telling devices. Market participants should remain aware that deviations from modeled paths are not failures of the models per se, but opportunities to refine assumptions and blend traditional finance tools with emerging onchain metrics. In a landscape as dynamic as cryptocurrency, relying solely on historical patterns without accounting for novel variables — such as the impact of spot ETFs, macroeconomic tightening, or geopolitical risk — could lead to costly miscalculations. Ultimately, the S2F and Rainbow frameworks offer compelling narratives, but the final verdict will be written by market forces.