Crypto glossary
Pi Cycle Top indicator
The Pi Cycle Top indicator flags a likely bitcoin cycle peak when the 111-day moving average crosses above twice the 350-day moving average.
Created by analyst Philip Swift in 2019, the indicator compares a fast and a slow moving average of bitcoin's price. The 111-day average tracks recent momentum; the 350-day average, multiplied by two, represents an overheated level relative to the longer trend. When the fast line rises through the slow one, the market has risen unusually far, unusually fast. The name comes from the ratio 350 divided by 111, which is close to pi.
Back-tested, the crossover landed within days of the bitcoin price peaks of 2013 and 2017, and it triggered again in April 2021, close to that year's first major top. That record made it one of the most watched cycle-top signals on charting sites and social media.
It also illustrates the limits of such tools. The indicator did not signal the second, higher peak of November 2021, its parameters were chosen to fit past tops, and each cycle has had lower volatility and smaller multiples than the one before. A crossover can still be followed by further gains; at best it marks an extreme reading, not a precise sell date.
Example
In April 2021 the 111-day average crossed above twice the 350-day average; bitcoin fell sharply within weeks, but a new high in November came without a fresh signal.