One thing I know for certain is that tracking cryptocurrency transactions is practically impossible, and this is because crypto currencies are untraceable. So with regards to this, if any “hacker” approaches you with the promise of recovering bitcoins lost to investors is probably lying to you. Because of how cryptocurrency works, there are only a few logs made and these are solely for the purpose of keeping tabs on transactions (like a monthly bank statement). Money transferred to third parties through blockchain cannot be recovered because this money has left your wallet and is now in another wallet (it simply doesn't exist anymore). In order to actually make up for losses in trading, there is the option of mining bitcoins, but this is a very huge task and is usually undertaken by licensed companies and agents and miners who have acquired a license for the transaction of crypto currency as legal tender from the various authorities in their location or country. So you see, recovering your lost funds can only be carried out by a few services. These services have the backup of a financial institution which validates their license. And one more thing, sometimes depending on the amount of money lost, the mining process can take long periods of time, and yes, payment has to be made before the process begins (usually a certain percentage of the amount to be recovered). Luckily, because these agents are registered with a trusted financial institution, some part of the payment (sometimes half) can be made on your behalf, but has to be repaid after the recovery (like a loan) this is because the miners have to be paid. I know this much because I had to do as much research as possible when I was in a similar situation and didn't want to be another victim. In the end, I worked with oxomar, a licensed agent who helped me recover from my losses (OXOWEALTHRECOVERY). I lost $15,000 to a fake investor who just went AWOL once I had made the transfer. At the time, I couldn't afford the cost for the service, so his institution offered a loan which I paid back once the mining was complete. It took sometime, but it was well worth it. I hope this helps.