Bitcoin 500-Day Cycle

Bitcoin cuts the miner block reward in half every 210,000 blocks — roughly every four years. BTC500 does not try to pick the exact bottom or top of that cycle. It measures one fixed window around the event and shows what historically happened inside it.

T-500 is the calendar day 500 days before a halving. T+500 is the calendar day 500 days after it. The window is about 1,000 days long. Cycles are compared by lining those two dates up across the 2012, 2016, 2020, and 2024 halvings, using the same daily price archive as the simulator.

The 500-day span is a simple, auditable rule — not an optimized curve-fit. It is long enough to include the pre-halving stretch and most of the historical post-halving advance, and short enough to leave the later drawdown outside the window. Other windows exist. This one is published so it can be checked.

Historical performance is not a guarantee of future results. Four halvings is a small sample. Later cycles have produced smaller multiples as Bitcoin matured. The next window can be better, worse, or fail.

4 completed windows in this archive finished higher at T+500 than at T-500. The simple average of those window returns is +1959%. That average is a description of a small sample, not a forecast.

The largest completed multiple was the 2016 Halving (+3318%). The smallest was the 2024 Halving (+560%). After the earliest windows, later cycles started at a higher Bitcoin price and the same rule produced a smaller multiple.

The move from T-500 to the halving date was not uniformly positive. The table above is the record; it is not an argument that the next pre-halving stretch must rise.

Between T+500 and the next T-500 the rule is in cash. That gap historically covered the 2018 and 2022 drawdowns. It also means the rule did not own Bitcoin in those stretches. Compare the same dates against buy-and-hold in the simulator before treating the cash window as an advantage.

BTC500’s historical entry is T-500 — 500 days before the next estimated halving. The live date for the current cycle is December 4, 2026. It will move if blocks run faster or slower than ten minutes.

That date is a rule, not a claim that it is the best day, the cheapest day, or the right day for a given person. Some investors buy earlier. Some wait until after the event. The point of publishing T-500 is that it can be backtested. Open the simulator on a $500 or $1,000 starting amount to see what that rule did in previous windows.

BTC500’s historical exit is T+500. For the current estimated halving that date is August 30, 2029. The rule does not sell before the halving and does not trail a moving average. It uses one calendar date.

T+500 is not a forecast of the cycle top. In some completed windows price was still advancing at that point; in others the strongest months were already behind it. Selling then also means sitting out until the next T-500. That is a tradeoff, not a guarantee. Nothing on this site is financial advice.