BULL MARKET: natural growth driven by real economics
BUBBLE: unnatural growth driven by an influx of money supply during a bull market
In the context of the current bull run in crypto, it was kickstarted by the Bitcoin halving (reduced supply), followed by institutional adoption (demand). Same with the rise of DeFi, which caused a rise in demand for ETH to pay for gas fees – this is natural growth.
Since the early players have already made money on the big caps, new market entrants want to look for new opportunities. In crypto this translates as buying altcoins (hence alt season always comes after Bitcoin etc, have reached ATH’s).
As alt season progresses, we start to enter bubble territory. This influx of money supply starts to get thrown at “cheap” alts with low market caps resulting in pumps. During peak alt season (like in 2017) you can pretty much buy any coin in the top 100 and it will pump. Most of these coins don’t have the fundamentals to back up their valuations, so it’s completely unnatural growth.
Eventually the bubble pops and money starts to flow out of the market, triggering a bear market.
The crypto market seems to move in 4 years cycles (3 year bull market, 1 year bear market) in line with bitcoins [halvings](https://news.bitcoin.com/between-bitcoin-halvings-bitcoins-price-not-bound-4-year/). That would put us in the last year of this cycle.