So-called “sleeping bitcoins” have been waking up in September, and there’s still a chance the month could break August’s record-setting movements. Last month, Bitcoin.com News reported that 6,427.59 BTC, valued at more than half a billion U.S. dollars, moved for the first time in years.

While the first few days of September started off slow, the month has now witnessed 3,790 sleeping bitcoins from wallets created between 2010 and 2017 wake up from slumber, according to btcparser.com stats.

The wallet that moved today was first created on Sept. 27, 2013, making the address nearly 13 years old. Bitcoin’s price was around $128 per coin on that day, which means the 113 BTC was valued at $14,464, compared with today’s $8.8 million. This specific transfer and several others this month have pushed September’s numbers a lot higher.

The biggest spend so far this month was derived from a wallet first created on July 9, 2016. It shifted a third of the month’s volume of dormant BTC moves so far by shifting 1,260.776 BTC on Sept. 6. Wallets from 2016 dominate the sum of BTC spent due to that specific transfer alone, and over the first 14 days of September, 1,450.83 BTC was spent from 2016 addresses.

A very distinct and ancient 2010 cluster of unspent transaction outputs (UTXOs) shifted around 600 BTC on Sept. 5. Across the month’s whole data set, BTC dormancy averaged around 13 years. The dormant spending shows weekend-heavy activity, meaning 62% happened on Saturdays and Sundays.

The weekend concentration of these awakenings suggests these movements are more likely deliberate than reactions to spontaneous market moves. Although higher bitcoin prices do help, that, too, may have swayed these vintage coin movements. At the end of the day, we don’t know why old-school holders move when they do, but we can see exactly when they do.