Bitcoin Nears Best September on Record as Monthly Close Hinges on Final Day

Bitcoin is on track to finish September with its strongest gain in the thirteen years CoinGlass has tracked the month, but the outcome is not locked in yet.

The cryptocurrency has climbed 7.33% since the month opened, according to CoinGlass data. That is a fraction ahead of September 2024's 7.29% return, a margin narrow enough that a single day of price action could dissolve the record.

September has historically been unkind to bitcoin. The month closed lower in eight of the years from 2013 through 2025, including a six-year losing run from 2017 to 2022. Even with this year's advance, September still carries the worst average return of any month at minus 2.34%. The pattern has loosened in recent years: bitcoin gained 3.91% in September 2023, 7.29% in 2024 and 5.16% in 2025, so a positive close this year would extend the month's green streak to four.

The moon's reputation for weakness is not confined to digital assets. The S&P 500 has also averaged a loss in September going back to 1945, with explanations ranging from post-summer trading lulls to tax-loss selling.

Bitcoin entered September near $78,500, fresh off a 25% August surge. Mid-month dealt two blows within 48 hours. On Sept. 15 the Senate's Clarity Act fell short on a cloture vote, 49 to 50, and spot bitcoin ETFs recorded $450.4 million of net outflows, their heaviest single day since June. The Federal Reserve followed on Sept. 16 with a quarter-point rate increase to a 3.75%–4% target range, its first hike since 2023. Crypto and equities tend to react to rate shifts because borrowing costs for speculative positions move with them. Bitcoin slid to roughly $75,000 after the decision, and it looked as though September would close red once more.

Then sentiment reversed. ETFs absorbed about $2.98 billion across seven consecutive sessions, including close to $1 billion on Sept. 21 — their largest daily intake since October 2025. More than $800 million in short positions were liquidated in a 24-hour window as rising prices forced bearish traders to buy back, and bitcoin reached $87,354, a level last seen in late January.

A shallow pullback so far

About 4% of that rally has since been surrendered. On Monday bitcoin slipped to $83,000 as Brent crude pushed back above $100 following President Donald Trump's rejection of Iran's conditions for reopening the Strait of Hormuz.

Technical readings remain constructive even after the dip. Fibonacci retracement levels, which gauge how much of a prior advance a pullback has retraced, place support and resistance between $74,978 and $87,354. The Average Directional Index, a measure of trend strength on a 0-to-100 scale that does not indicate direction, reads 42.3, comfortably above the 25 mark traders use to call a trend established. The Relative Strength Index, a 0-to-100 momentum gauge where readings above 70 signal overheated buying, sits at 61.2. The 50-day moving average also remains above the 200-day, the configuration known as a golden cross. A break below $82,626 would put the $81,166 to $79,705 band — the 50% and 61.8% retracement levels — in play next.

A green September would not repair the year for holders. Bitcoin is still roughly 4.4% under the near-$87,497 level where it started 2026. A year ago, a positive September was followed by a 3.69% October decline and a fourth-quarter drop of about 23%. The Fed's remaining meetings are scheduled for Oct. 27-28 and Dec. 8-9. To preserve the monthly record, bitcoin needs to close above approximately $83,600.