Same finish, very different ride

1. Both endpoints were chosen, and both favor the index. The comparison starts on the day Bitcoin crossed above the index, which by construction is a day Bitcoin had just outrun it. Bitcoin had tripled in the three months into that day. The comparison ends today, when the S&P sits 1% from its all-time high and Bitcoin sits 37% below its own. The ratio of the two has ranged from 0.40 to 1.91 since the crossing and spent 52% of days above 1. The "equal" reading is one point on that path.

Run the identical test from the same start date to July 2025 and Bitcoin is up 206% against the S&P's 65%. Run it to November 2022 and Bitcoin is down 60% while the S&P is up 4%. Move the start back one quarter and Bitcoin wins by 500 points. Move it forward one quarter and the index wins. A verdict that flips with a one-quarter nudge is a date, not a finding. That cuts both ways, and section 4 turns the same test on the windows that favor Bitcoin.

2. "High correlation" is not what the data shows on ordinary days. Correlation measures how much two assets move together, from 1 (in lockstep) through 0 (unrelated) to -1 (in opposite directions). Since 2021, Bitcoin's correlation to the S&P has been 0.38 on daily moves and 0.26 on weekly moves. Nor does the figure rise on bad days: on days the S&P fell 1% or more it was 0.34, and in the worst tenth of weeks it was 0.23. A correlation measured only on down days runs low by construction, because it strips out the index's own variation, which is why the hit rate in the previous section, Bitcoin falling on 77% of those days, is the fairer stress measure. Put the two together and the picture is consistent: Bitcoin usually falls when stocks fall hard, and on the other 90% of days it goes its own way. That moderate correlation is one of the two numbers the "dud" claim rests on, the other being the return, and it is the one that decides what Bitcoin does inside a portfolio.

3. The textbook rule gives the opposite answer. Portfolio management does not judge an asset on its own Sharpe ratio. It judges what the asset does to the portfolio. The table runs the critics' own windows, with the index carrying its dividends, and adds a Bitcoin slice rebalanced daily. Daily rebalancing credits the volatile sleeve with a rebalancing gain that a buy-and-hold slice would not earn, so the blend rows lean slightly in Bitcoin's favor by construction.

In the ETF window the 3% slice that the live debate keeps mentioning changes nothing to two decimals, a 5% slice raises the portfolio's Sharpe ratio and leaves its worst drawdown unchanged, and a 10% slice adds return but gives the Sharpe gain back. Since the 2021 crossing both slices raise return and Sharpe and cost two to five points of drawdown. Start instead at Bitcoin's November 2021 peak, the worst start the critics could pick, and the Sharpe gain disappears while the drawdown cost stays. That is the honest range: an asset with the same return and a correlation near 0.4 improves a stock portfolio a little, at a small cost in the worst stretch, and the improvement disappears if you buy it at a cycle top. None of that is a dud. A dud is an asset with the same return and a correlation near 1.

4. The window length picks the answer, in both directions. Bitcoin has historically moved in roughly four-year cycles. A 2.6-year window catches part of one. Even the 5.6-year window since 2021 starts at a peak. Stretch the test to 8 years, with the index carrying its dividends, and Bitcoin's Sharpe ratio is 0.52 against the index's 0.60, still behind. At 10 years it is 0.92 against 0.68. At 5 years, a window that starts ten weeks before the November 2021 peak, it is 0.15 against 0.58, the worst reading of the three. The 8- and 10-year windows start near Bitcoin's 2018 and 2016 lows, so they carry the mirror of the critics' start-date problem. Applying the same nudge test to them: of the 33 eight-year windows that start in each month from January 2016 to September 2018, Bitcoin's Sharpe ratio beat the index's in two-thirds, and lost in the third that start near the 2017 and 2018 peaks. No single window settles this. What the grid shows is that a third of eight-year starts produce the critics' answer, and that the starts which do are the ones at or near a peak. The critics' windows are shorter and start at one. The reader should know that before adopting their answer.

5. Measured against its own long-run trend, Bitcoin is sitting where past cycle lows sat, not where highs sat. The four points above are about the windows. This one is about where in its own cycle Bitcoin was when the critics measured it, and it needs a short explanation of the tool. Bitcoin's price has not grown at a steady percentage each year. It has grown along a curve called a power law: price rises as a fixed power of the asset's age, so each year's percentage gain is a little smaller than the last, but the curve never flattens out. Fit that curve to sixteen years of daily prices and it explains about 96% of the variation. The fitted exponent is about 5.6, and it has barely moved whether you fit it on data ending in 2017, 2020, 2023 or today. Nobody knows for certain why Bitcoin has followed this shape. The usual explanation is that a network's value grows with the square of its users, and its user count has grown as a power of time. Whatever the cause, the curve has held long enough to be a useful yardstick for asking whether a given price is high or low for its date.

The price does not sit on the curve. It swings around it in cycles, running far above the curve at each cycle's peak and well below it at each trough. The gap between price and curve is what tells you where in the cycle you are.

The last three cycle lows bottomed between 0.44x and 0.47x the curve, and the 2015 low reached 0.38x. The June 2026 low was 0.44x. Today's 0.56x is lower than 83% of all trading days since 2013 and lower than 91% of days since 2017. That is the basis for saying Bitcoin is in the lower part of its range: not a feeling, but the price sitting at the depth where the last three cycle troughs sat.

That is also what the ETF-era comparison is actually measuring. Bitcoin started the ETF window at 0.83x the curve, rose to 1.35x at the December 2024 peak, and ended it at 0.56x, below where it started. The curve itself rose 149% over those 2.6 years. The price rose 69%. The critics measured Bitcoin during a stretch when it was losing ground against its own trend, and that stretch happened to end level with an index sitting 1% from its all-time high.

One more fact cuts the other way, and it belongs here. The peaks are getting lower: 6.5x, then 3.6x, then 1.35x. The 2025 cycle never got far above the curve at all. That is consistent with a maturing asset whose swings are shrinking, and it means a reader should not expect the next peak to look like 2017. The lows, though, have held their depth. If the lows keep holding while the highs compress, the curve is still the right yardstick and today sits near its floor. If the next low breaks well below the 2015 mark, the yardstick is broken.