The 2020/2021 and 2024/2025 crypto bull runs both followed Bitcoin-halving rhythms, but they differed in narratives, institutional channels, and altcoin relative strength. Spot prices and indexes cited below are mostly historical snapshots (often around early/mid-2025 where noted)—not live quotes.
For context on long-horizon returns: Bitcoin once traded near 1 of BTC from that era through later cycle peaks would have produced extreme paper gains in retrospect. That historical illustration is not a forecast, and past bull-run returns do not guarantee future results.
So what is a crypto bull run, and how does 2020/2021 compare with 2024/2025?
A crypto bull run is a period of significant price appreciation in a cryptocurrency’s cycle. This massive price appreciation often spreads across most cryptocurrencies but is most noticeable in Bitcoin, the largest crypto asset by market capitalization.
Historically, most crypto bull cycles kick off months after Bitcoin halving, that is, when Bitcoin’s mining rewards are slashed by half. The theoretical correlation between Bitcoin halving and the birth of a bull run syncs with the economic principle of demand and supply.
As an asset’s supply reduces, its price could increase as a result of expected scarcity. Multiple bull cycles have birthed an explosive appreciation in Bitcoin’s price.

Source: TradingView
Some market factors that contributed to the growth of the cryptocurrency market in 2020 and 2021 include the halving of Bitcoin, Elon Musk’s crypto advocacy, and retail investors’ peaked interest in memecoins, the metaverse, and play-to-earn tokens.
The 2020 Bitcoin halving occurred on May 11th. In the months that followed, Bitcoin’s price surged significantly. Bitcoin rose by about 12% the week after its halving, and the flagship currency recorded a value appreciation of over 650% one year after the halving event.
The halving of Bitcoin reduced its mining rate, making miners extract half the quantity of BTC they once got from mining. For miners to maintain their profit margin, Bitcoin’s price has to appreciate by at least 2x. Hence, halving is always seen as a trigger for price appreciation.
The halving also had a positive ripple effect on other cryptocurrencies. Altcoins like Ethereum, Cardano, Solana, and Litecoin surged in value months after Bitcoin’s halving. Notably, though, XRP’s price struggled in 2020 due to the SEC lawsuit against Ripple. Overall, the general cryptocurrency market experienced a massive surge in value and capitalization.
On January 29, 2021, the crypto ecosystem went ecstatic when Elon Musk, the world’s richest man at the time, updated his X (formerly Twitter) bio. He simply used the word “Bitcoin” along with its symbol on his bio and tweeted a cryptic message: “In retrospect, it was inevitable.”
Following his tweet, Bitcoin’s price surged by 20%. A few weeks later, Musk announced that his company Tesla would begin to accept Bitcoin payments, and all BTC received by Tesla would not be converted to USD. Musk’s open support for Bitcoin attracted more retail and institutional investors to the crypto ecosystem.
Interestingly, Bitcoin adoption was only the beginning of Elon Musk’s crypto escapades in 2021. The American billionaire also added Dogecoin to his bio, posted numerous dog memes, and openly expressed his support for the memecoin. Although Dogecoin has existed since 2013 and has primarily been seen as a coin with no fundamental value, given its creation circumstances, Musk’s support for DOGE changed this stigma in no time.
Dogecoin recorded an 800% gain a few days after Elon Musk’s first notable tweet about Doge. This explosive surge had a positive impact on other dog-themed coins. Shiba Inu was the first to follow the Doge trend in price appreciation, and shortly after, multiple doge-themed memecoins were launched.
While Dogecoin took the lead in the memecoin frenzy, multiple other memecoins attracted retail investors and cruisers to the crypto ecosystem. Newbie investors were pushed by the fear of missing out (FOMO), and coin creators capitalized on this fear. New coins like Safemoon, Safestar, PIG, and Freedom coin caught the eyes of noobs.
New investors were drawn to these meme coins due to their low market cap, low value, and the potential for high returns. Further, most of these projects were accompanied by hype from crypto influencers. In March and April 2021, most of these newly launched memecoins saw gains of above 1000%. However, these gains were short-lived as they were birthed from the euphoria of the temporary memecoin craze.
Play-to-earn cryptocurrencies and metaverse projects brought a “unique flavor” to the crypto market in 2021. The idea of playing to earn crypto tokens that could be converted to real money was welcomed with ecstasy in the crypto ecosystem.
The Axie Infinity game was the leading P2E crypto project in 2021. Players had to battle monsters or other players to earn the SLP token which could then be converted to cash. This attracted multiple gamers to the crypto ecosystem.
Metaverse projects had a different model. They incentivized users to develop digital real estate. These digital versions of real estate could then appreciate in value or be resold to other users.
Both play-to-earn games and metaverse projects like Decentraland and Sandbox unlocked a new way to earn in the blockchain space. Although these projects gained unprecedented traction, both models were eventually unsustainable.
2021 was the year for “Ethereum killers.” Ethereum had always been the leading altcoin, but it seemed like Ether would be overthrown in the 2020/21 bull cycle. Relatively newer cryptocurrencies like Luna, Solana, and Avalanche quickly gained more traction.
The rise in the adoption of these crypto projects was primarily due to the increased network congestion on the Ethereum network. Gas fees on the Ethereum network averaged 0.1 on average.
Ethereum users expected the Ethereum merge (which enabled the transition from Proof-of-Work to Proof-of-Stake) to contribute to Ether gas fee reduction. However, at the time, Ether holders were still in the dark regarding a specific date for the merge. Eventually, the Ethereum merge took place in September 2022, but Ethereum killers had already stolen a portion of the DeFi limelight in 2021.
Lots of developers and end users flocked to the Solana, Luna, and Avalanche ecosystems, which brought in “new money” or investment into the altcoin market in 2021. “Ethereum Killer” projects particularly boomed between September and November 2021, with most coins reaching their all-time high.

Source: TradingView
Like every bull cycle, the 2020/21 cycle did not last forever. The prices of Bitcoin, Ethereum, and other cryptocurrencies took a downward spiral towards the end of 2021. In December 2021, Bitcoin’s price tanked by 20%. At first, that seemed like a regular pull-back. Time eventually revealed that it was just the beginning of a cataclysmic downtrend.
In 2022, the crypto ecosystem welcomed more woes. Bitcoin had an opening price of 16,500. Several factors contributed to this downward spiral. For one, many cryptocurrencies were already overpriced at the end of 2021.
Also, a series of negativities contributed to the decline in the value of Bitcoin and altcoins. For example, the Luna and UST debacle injected an unhealthy level of fear into the crypto ecosystem. Further, the crash of FTX, one of the largest crypto exchanges at the time, dealt the final blow to FTT’s price and, by extension, Solana’s price. This also had a domino effect on other cryptocurrencies, as retail and institutional traders massively sold off the bulk of their crypto assets. It wasn’t until 2023 that the crypto market gradually showed signs of recovery.

Source: TradingView
Some significant events that have taken place during the 2024/25 bull market include the approval of spot BTC and ETH ETFs by the US SEC, Bitcoin’s fourth having, the rise of AI agents, and the U.S. President’s support for cryptocurrencies.
On the 10th of January, 2024, the United States Securities and Exchange Commission announced that it had approved the issuing of spot Bitcoin ETFs. This marked a major milestone in the history of Bitcoin. Although Bitcoin’s price did not appreciate significantly following the ETF approval, crypto advocates accepted this approval as the start of positives in the crypto ecosystem in 2024.
In May 2024, just a few months after the approval of spot BTC ETFs, the U.S. SEC again approved spot Ether ETFs. The approval of Bitcoin and Ether ETFs solidified the status of both cryptocurrencies as leading digital assets globally, especially for retail and institutional investors in the United States.
Bitcoin’s fourth halving occurred on April 19, 2024. That event reduced block rewards to 3.125 BTC per block. Crypto holders expected historical patterns to repeat. Interestingly, about eight months after Bitcoin’s fourth halving, the flagship currency reached the $100,000 mark, a milestone that has long been expected. Bitcoin’s next halving will take place in 2028.
The U.S. SEC has established a reputation as one of the leading antagonists of cryptocurrencies in the last few years. In December 2020, the SEC sued Ripple for raising $1.3 billion through an unregistered securities offering. The battle between the SEC and Ripple, which went on for years, put the US organization in the limelight. However, in 2023, the Securities and Exchange Commission lost its lawsuit to Ripple.
Going forward, the SEC probed Yuga Labs, the company behind the BAYC NFT collection, and opened a lawsuit against Coinbase and Kraken. Coinbase and Kraken were accused of illegally operating an exchange and selling unregistered securities.
In March 2025, the SEC dropped its charges against both crypto exchanges. That March 2025 set of decisions suggested a potential regulatory shift in how U.S. regulators perceived certain cryptocurrencies and crypto organizations.
According to data from Coinmarketcap, over 400 cryptocurrencies are directly or indirectly linked to artificial intelligence. AI tokens have existed for a few years now, but it was until 2024 the first set of crypto AI agents were launched.
AI Agents have unique traits that distinguish them from regular artificial intelligence tools. They can autonomously perform tasks on behalf of a user or another system. For example, “Dolos the Buly” is an AI agent that scans for mentions on X (formerly Twitter) and sarcastically or humorously responds to threads to maximize engagement.
Several innovators have capitalized on blockchain technology to create AI agents and an accompanying token. Although still in its infancy, this innovation has gained traction. The market capitalization of AI tokens reached $70 billion in June 2024.
After Donald Trump won the 2024 U.S. election, many crypto advocates expected a more constructive policy tone. During his 2024 campaign, Trump had signaled support for crypto industry development.
The Trump token (TRUMP) launched in January 2025 as a crypto asset celebrating the U.S. president. In its first week it outperformed most peers: within about 24 hours, TRUMP moved from as low as about 75.3, drawing heavy short-term speculation.
On March 7, 2025, Trump signed an executive order related to establishing a strategic Bitcoin reserve. At the time, the move did not necessarily lift BTC spot prices immediately, but it reinforced a policy narrative for some investors. Later policy and market outcomes should be tracked separately rather than extrapolated from early-2025 sentiment.

Source: Bitbo.io
Bitcoin’s price trajectory in the 2020/2021 bull run is similar to the 2024/25 cycle. Firstly, BTC’s price did not surge exponentially immediately after its halving. The 2020 halving was on the 11th day of May, but it was not until November 2020 that the leading cryptocurrency broke out from its price range. BTC was valued at around 18,900 recording a 37.9% increase that month. Bitcoin closed the year trading at around $29,000.
In 2024, the Bitcoin halving took place on April 19. However, it was not until November 2024 that BTC’s price ramped. Like the previous halving year, BTC appreciated by 37% in November 2024.
Secondly, significant price corrections occurred during the 2020/21 and 2024/25 bull cycles. For example, between April and July 2021, Bitcoin’s value crashed by over 50%. Eventually, the cryptocurrency recovered and created an all-time high in November 2021. Likewise, the 2024/25 bull run has been accompanied by a significant pullback. A 30% price crash is evident when we compare BTC’s high in December 2024 with BTC’s low in March 2025.
The huge price corrections experienced in both cycles reveal that pull-backs are typical even in a bullish market.

Source: Blockchain Center
While Bitcoin printed cycle highs in both the 2020/21 and 2024/25 observation windows, altcoin relative performance diverged. Using data around early 2025, only a few of the top fifty cryptoassets—such as Solana (SOL) and the Gate token (GT)—had made fresh all-time highs. Solana printed a new ATH on January 19, 2025, aided in part by TRUMP-coin hype on Solana. The Gate token also showed relative strength across 2024–2025 at various points.
Ethereum traded above 1,800—about 62% below its November 2021 ATH. Under the same snapshot lens, Dogecoin, Cardano, and Avalanche were roughly 77%, 78%, and 86% below their ATHs (levels move; treat these as a dated cross-section).
The altcoin season index (top-50 altcoins vs Bitcoin, via Blockchain Center) was near 22% around March 2025. It briefly rose above 75% in the first week of December 2024, then faded. That reading is not a live “currently 22%” claim.
By contrast, in 2020/21 more than 75% of altcoins outperformed Bitcoin between August and September 2020, and the index stayed above 75% for months between March and June 2021. Across these two windows, altcoins were relatively stronger in 2020/21 than in the early 2024/25 stretch.

Source: TradingView
The chart above illustrates BTC/USDT on the daily timeframe from the article’s drafting window (around early 2025). At that time, price had formed a classic double-top bearish pattern, broken the neckline, and market commentary pointed toward a demand zone below about $70,000—where stronger buying could, in theory, support a reversal.
This is a reading of that historical chart, not a forecast for later dates. Bitcoin responds to macro, liquidity, and policy headlines; cross-check public price charts yourself. Nothing here is financial advice.
The 2020/2021 and 2024/2025 crypto bull runs both tracked Bitcoin-halving rhythms, but narratives, institutional rails, and altcoin relative strength diverged. Prices and indexes cited here are mostly historical snapshots (often around early/mid-2025)—useful for structure, not as live quotes or trade signals.
A period of sustained crypto price appreciation and rising risk appetite, usually most visible in Bitcoin and sometimes spilling into altcoins.
Both relate to post-halving supply dynamics, and both included deep drawdowns—bull markets are not one-way streets.
Narratives and capital mix differ: 2020/21 leaned retail meme/meta themes; 2024/25 put more weight on spot ETFs, compliance rails, and institutional participation (varies by phase).
No. Treat most figures as dated snapshots (often around March 2025) and verify public charts yourself.
Across these two windows, altcoins were relatively stronger in 2020/21 than in the early 2024/25 stretch; single-asset outcomes still diverge widely.





