What Does "Everyday is Zeroday" Mean?

What happened at Binance

On October 29, 2026, someone broke into Binance (the world’s biggest crypto exchange) and stole a huge amount of money — Binance says about $6.3 billion. That’s the biggest crypto theft ever recorded.

The attackers didn’t steal the secret keys that normally protect the wallets. Instead, they got into one engineer’s laptop. From there they reached systems that control withdrawals and used those systems to send money out of Binance’s “hot wallets” (the online wallets used for everyday transfers). The money left across several blockchains, mainly Ethereum, Bitcoin, and TRON.

Binance quickly paused deposits and withdrawals. With help from other companies (like the ones that issue stablecoins), they managed to freeze about $3 billion of the stolen funds so the thieves can’t move that part. Binance says it will pay back all the losses itself so users don’t lose their money. It also says it found no evidence that the actual private keys were stolen.

What Elon said

Elon Musk replied to a report about the hack with just three words:

“Everyday is Zeroday”

What that means in plain English

A “zero-day” is a security hole that nobody who runs the system knows about yet. The attackers find it first and use it before anyone can fix it. The name “zero-day” means the defenders have had zero days to prepare.

Elon’s point is that these kinds of surprises aren’t rare anymore. In big, complicated computer systems (especially ones that hold a lot of money), new unknown weaknesses show up so often that it feels like there’s a fresh one every day. This Binance incident is a real-world example: one compromised laptop was enough for attackers to move billions, even without stealing the main keys.

He had said something almost identical a couple of days earlier, so this was him pointing out the same ongoing problem when the Binance news broke.

Why it matters

Exchanges need hot wallets so people can withdraw money quickly. That makes them convenient but also risky, because those wallets are online. When someone finds a way in through an employee’s computer or an internal system, the losses can be enormous. Even when the exchange promises to cover the losses, events like this shake confidence and show how hard it is to fully protect large digital systems.