The question comes up before anything else, and the useful answer is the one that separates the risk that lives in the platform from the risk that lives in the setup, because they are different risks and they need different answers.
The record
The market has run since November 2023 without a break, and the unbroken run is the record. It stayed up through outages that took other markets down, vendors kept migrating in, and the review histories came with them. A record like that is not a guarantee. A guarantee is a claim, and claims are marketing. But a record is evidence, and evidence is what you can actually build a judgment on. Three years of continuous operation in this space is more than most of the competition can show.
Where the risk actually sits
The platform's share of the risk is the escrow. Your deposited coins sit in wallets the market controls until you release them, and that is true of every escrow market, Nexus included. It is a real exposure, and it is the reason the standing advice is to keep only what you plan to spend on the platform and withdraw the rest. Beyond the escrow, the platform does not hold your identity, your device, or your coins in any other form.
The setup's share of the risk is everything else, and it is the larger share. A mistyped address lands you on a clone, and the clone takes the password. A reused password is a password that has already been taken somewhere else. A balance that sits for weeks is an exposure that compounds by the day. None of these are the platform failing. All of them are the setup failing, and all of them are fixable with habits that take seconds.
The setup that keeps it low
Five seconds before every login: read the address in the bar from the end backwards and compare it with the one you copied. A long password you have never used anywhere, and two-factor authentication turned on in the first session, with the recovery codes written down and tested once. Deposits sized to the order, paid from a personal wallet, with the rest withdrawn. Delivery details encrypted with the vendor's key.
Each of those is a small thing, and together they are the difference between a market session that is as safe as this kind of transaction gets, and one that hands the loss to the first clone or the first keylogger. The security basics walk through the full stack, and the phishing guide covers the failure mode that costs the most.
The answer
Safe, in the sense that the platform has a record, a vetted vendor base, escrow on every order, and dispute handling that is fast by the standards of the space. Not safe in the sense of risk-free, because nothing in this category is risk-free, and the risk that remains is the setup's, not the platform's. Do the setup, and the question answers itself.