Bitcoin's rough late-summer pattern is back in focus, and history leans bearish heading into September.

• August and September together have closed lower in eight of the last 12 years, making the pair a weak spot for Bitcoin.
• September on its own is Bitcoin's worst month historically.
• The bright side comes later: October averages a near-20% gain and the fourth quarter is up in most years.
• Much of that strong seasonal record is skewed by the wild early years, and pre-2017 data is arguably too old to trust for today's market.

Outlook: Expect possible weakness through September before the historically stronger fourth quarter, but the older stats are worth taking with caution.