&gt;I think you&#x27;re under the assumption that currency conversions are traceable.<p>I was specifically addressing tumbling services. I&#x27;m guessing that you accept those services are easy to compromise (heck, for all we know, various governments might operate the current ones) which is why you bring up currency conversion.<p>&gt;For example: 20 BTC -&gt; $4000 -&gt; 25000 yuan -&gt; 4 new addresses @ 5, 10, 2, &amp; 8 BTC<p>Let&#x27;s turn this around: you have a list of transactions, you know when they took place, you know where the money ended up, and now you&#x27;re tracing the line backwards, knowing that at some point, there will be a connection (or connections) to other transactions <i>at least as big as this one</i>; why do you think this is so hard to analyse?<p>&gt;The only way to trace these is to compromise the exchange servers, get bank account information, and get transactions from the banks. Very difficult to do given the international nature of these exchanges.<p>Not really, given how little is known about some exchanges&#x27; operators.