Someone tells you they want to acquire your company.

You get excited. Of course you do. You start opening up – sharing financials, roadmaps, customer data, strategic plans. The due diligence process begins. Weeks pass.

Then the deal quietly dies.

What just happened? You ran into one of the most underestimated risks in any M&A process: the Fishing Expedition.

Peter Möllmann is a partner at PXR, one of DACH’s leading tech M&A law firms, and has advised on some of the largest tech exits in the region. In a recent three-hour deep dive on the DEALMACHER Podcast, he described the Fishing Expedition as something that happens more often than founders think – and almost always at their expense.

What a Fishing Expedition actually is

A Fishing Expedition is when a potential buyer – often a direct competitor – initiates an acquisition process not because they intend to buy, but because they want access to your information. An indicative offer is easy to write. It costs nothing. And it gets founders to open doors that should stay closed.

A competitor sends over an attractive number, everyone gets big eyes, and suddenly you’re sharing things you’ll regret.

The two warning signs

According to Peter, you can’t always know for certain – but two signals are reliable early indicators.

The first is resources. A serious buyer brings serious people. External advisors, dedicated deal teams, real due diligence infrastructure. A competitor running a Fishing Expedition typically does it with internal resources only. No external bankers. No independent counsel. They’re keeping costs low because they’re not actually buying.

The second – and more telling – is information asymmetry. A real buyer accepts mutual transparency. They share information about themselves too: integration plans, organizational structure, strategic rationale. A fishing buyer only wants to receive. When you push back and ask for reciprocal disclosure, you hit a wall. That asymmetry is the clearest signal the process is not what it appears to be.

Why founders fall for it

The psychology is straightforward. An indicative offer on the table feels like progress. It feels like validation. After months or years of building, someone is finally saying your company is worth something real. Walking away from that – or even pausing to question it – feels like throwing away an opportunity.

Peter’s advice: the moment you sense one-sided transparency, you have to be willing to stop the process. Even if there’s an offer on the table. Even if it hurts.

The legal dimension you probably don’t know about

There’s a second layer to this that most founders miss entirely. When the interested buyer is a direct competitor, European competition law – specifically antitrust regulation – severely restricts what information can be exchanged at all. You cannot freely share pricing data, margin information, or revenue details with a competitor, even in a due diligence context.

The solution is often a so-called Clean Team: external advisors who review sensitive data on behalf of the buyer, aggregate it, and confirm assumptions without passing the raw information across. If a competitor-buyer isn’t proposing this structure, that itself is a red flag.

What to do

Before opening up to any buyer who is also a competitor: test them. Ask for reciprocal disclosure early. Watch whether they bring external resources or keep it internal. And if the process feels one-sided – trust that feeling. It probably is.

The Fishing Expedition Trap works because founders are conditioned to treat every inbound offer as an opportunity. Sometimes it is. And sometimes it’s just someone using your excitement to read your playbook.

Peter Möllmann discussed this and much more in my DEALMACHER Podcast – a two-part M&A masterclass for tech founders. Listen here.