<p>For large purchases, you should look at OTC (Over The Counter) Bitcoin markets. Also known as "dark pools".</p>

CC BY-SA 3.0
2018-02-28T06:01:07.770Z
2018-03-03T13:34:44.767Z
2018-03-03T13:34:44.767Z
alexg
<p>Buying that amount in person by cash is totally dangerous, you should buy that amount as parts. </p>

<p>if you are buying that amount online, if the seller is really a "bitconer" and he should know how to deal with multi-signature transactions.</p>

<blockquote>
  <p>Multisignature (multisig) refers to requiring more than one key to
  authorize a Bitcoin transaction. It is generally used to divide up
  responsibility for possession of bitcoins.</p>
  
  <p>Standard transactions on the Bitcoin network could be called
  “single-signature transactions,” because transfers require only one
  signature — from the owner of the private key associated with the
  Bitcoin address. However, the Bitcoin network supports much more
  complicated transactions that require the signatures of multiple
  people before the funds can be transferred. These are often referred
  to as M-of-N transactions. The idea is that Bitcoins become
  “encumbered” by providing addresses of multiple parties, thus
  requiring cooperation of those parties in order to do anything with
  them. These parties can be people, institutions or programmed scripts.</p>
</blockquote>

<p>Anyway, the skimmers around are much more than the real sellers, so you can't trust anyone. if you found someone, start by buying low amount and then you both high up the amount.</p>

<p>One more thing, You should wait the transaction to get at least 3 confirmations. Read more about <a href="https://en.bitcoin.it/wiki/Irreversible_Transactions" rel="nofollow noreferrer">Irreversible Transactions</a></p>

CC BY-SA 3.0
2018-02-26T08:31:31.367Z
2018-02-26T08:31:31.367Z
Tailer
<p>This is not only dangerous for you, but also for the people creating a transaction  with you. There is money laundering rules everywhere, and people would have to explain, where the huge amounts came from. Governments are chasing tax issues, and investigation services look for frauds of all kinds. </p>

<p>And then there were too many stories of African princes...</p>

<p>So, if the money is legal (clean source), you can easily go via exchanges. We as a community certainly won’t help in illegal activities. If it is not, then there is a major risk, that is not worthwhile to be taken.  Scams are all around the corner, and prosecutors as well. Bitcoin is maybe secure what concerns transactions, but anonymity an der privacy is not given per se. </p>

<p>Oh, for a little amount of 3-5% I might get interested helping to achieve your goals :-)
Did I just say that?</p>

CC BY-SA 3.0
2018-02-26T21:06:46.970Z
2018-02-26T21:06:46.970Z
pebwindkraft
<p>Try using <a href="http://www.localbitcoins.com" rel="nofollow noreferrer">www.LocalBitcoins.com</a>. They have designed the website to facilitate cash transactions via an escrow service. You can also see people buying and selling Bitcoin using cash, based on their location, in which you can filter those nearby. I would recommend doing a couple of bank transfers exchanges on the site first so you get a feel for the escrow service and you can also build up a little reputaion to build trust.</p>

CC BY-SA 3.0
2018-02-27T17:28:51.350Z
2018-02-27T17:28:51.350Z
Josh
<p>If a bitcoin address is the recipient of 1000 BTC (it is a utxo), and you send 0.00000001 BTC to someone, the transaction reveals the amount of bitcoin on that address, that address, the public key, and the remainder is sent back to the sender on a new address as change (minus transaction fees), a new address which has not revealed even its public keys yet, so no risk.</p>

<p>Many wallets will pick the smallest utxo to send from so if the wallet has received two transactions one for 1000 BTC, and one for 1 BTC and the wallet owner sends you 0.00000001 BTC then probably you will not be able to verify that they, in fact, have the 1000 BTC that they claim as the smaller utxo would be used.</p>

<p><a href="https://localbitcoins.com/" rel="nofollow noreferrer">https://localbitcoins.com/</a> is the website I was thinking of on which may people directly trade Bitcoin.</p>

<p>As others have said, you need to make sure that the BTC transaction is well confirmed before considering it final.</p>

<p>You might also consider using an escrow service.</p>

CC BY-SA 3.0
2018-02-27T08:55:52.333Z
2018-04-23T09:26:19.447Z
2018-04-23T09:26:19.447Z
Willtech
<p>Presumably, I want to buy Bitcoin in person somewhere in Europe. I need <em>very big</em> amounts, say, <strong>1K BTC</strong>, and I am willing to pay in cash (EUR). </p>

<p>When I find potential sellers online or through friends, I ask them to prove they have access to these amounts of BTC by sending me 1 satoshi from their accounts or by giving me some other proof. However, they all say that they don't just want to show their BTC accounts as it's unsafe and ask for a video of my cash, which I don't want to provide first to anyone. </p>

<p>How should I approach it? How are these trades usually done?</p>

CC BY-SA 3.0
2018-02-25T18:33:39.397Z
sounds dangerous. You could ask them to sign a message with their private key so that you can proove wheather they have the control of an address, so that they don't need to send you satoshis ( https://bitcoin.stackexchange.com/questions/3898/how-does-sign-message-work ) If they want to offer you 1k bitcoins, then they should send those 1k to a few addresses and proove that they are the owner. Everything else is dangerous for you. Don't let them scam you.
hardfork
CC BY-SA 3.0
2018-02-26T03:42:40.557Z
You may want to read Joseph Wang's [Back to paper and gold](https://bitquant.wordpress.com/2018/01/30/back-to-paper-and-gold/).
Rodrigo de Azevedo
<buy-bitcoins><cash>
Buying big amounts of Bitcoin for cash in person
bitcoinenthuUU
# Buying big amounts of Bitcoin for cash in person

(Asked by: username_0 on 2018-02-25)

Presumably, I want to buy Bitcoin in person somewhere in Europe. I need *very big* amounts, say, **1K BTC**, and I am willing to pay in cash (EUR).

When I find potential sellers online or through friends, I ask them to prove they have access to these amounts of BTC by sending me 1 satoshi from their accounts or by giving me some other proof. However, they all say that they don't just want to show their BTC accounts as it's unsafe and ask for a video of my cash, which I don't want to provide first to anyone.

How should I approach it? How are these trades usually done?

**Tags:** buy-bitcoins, cash

> **Comments:**
> **username_1**: sounds dangerous. You could ask them to sign a message with their private key so that you can proove wheather they have the control of an address, so that they don't need to send you satoshis ( https://bitcoin.stackexchange.com/questions/3898/how-does-sign-message-work ) If they want to offer you 1k bitcoins, then they should send those 1k to a few addresses and proove that they are the owner. Everything else is dangerous for you. Don't let them scam you.  
> **username_2**: You may want to read Joseph Wang's [Back to paper and gold](https://bitquant.wordpress.com/2018/01/30/back-to-paper-and-gold/).  

---

## 5 answers

### Answer by username_3 on 2018-02-28. Score: 1

For large purchases, you should look at OTC (Over The Counter) Bitcoin markets. Also known as "dark pools".


---

### Answer by username_4 on 2018-02-26. Score: 0

Buying that amount in person by cash is totally dangerous, you should buy that amount as parts.

if you are buying that amount online, if the seller is really a "bitconer" and he should know how to deal with multi-signature transactions.

> Multisignature (multisig) refers to requiring more than one key to
> authorize a Bitcoin transaction. It is generally used to divide up
> responsibility for possession of bitcoins.
>
> Standard transactions on the Bitcoin network could be called
> “single-signature transactions,” because transfers require only one
> signature — from the owner of the private key associated with the
> Bitcoin address. However, the Bitcoin network supports much more
> complicated transactions that require the signatures of multiple
> people before the funds can be transferred. These are often referred
> to as M-of-N transactions. The idea is that Bitcoins become
> “encumbered” by providing addresses of multiple parties, thus
> requiring cooperation of those parties in order to do anything with
> them. These parties can be people, institutions or programmed scripts.

Anyway, the skimmers around are much more than the real sellers, so you can't trust anyone. if you found someone, start by buying low amount and then you both high up the amount.

One more thing, You should wait the transaction to get at least 3 confirmations. Read more about [Irreversible Transactions](https://en.bitcoin.it/wiki/Irreversible_Transactions)


---

### Answer by username_5 on 2018-02-26. Score: 0

This is not only dangerous for you, but also for the people creating a transaction with you. There is money laundering rules everywhere, and people would have to explain, where the huge amounts came from. Governments are chasing tax issues, and investigation services look for frauds of all kinds.

And then there were too many stories of African princes...

So, if the money is legal (clean source), you can easily go via exchanges. We as a community certainly won’t help in illegal activities. If it is not, then there is a major risk, that is not worthwhile to be taken. Scams are all around the corner, and prosecutors as well. Bitcoin is maybe secure what concerns transactions, but anonymity an der privacy is not given per se.

Oh, for a little amount of 3-5% I might get interested helping to achieve your goals :-)
Did I just say that?


---

### Answer by username_6 on 2018-02-27. Score: 0

Try using [www.LocalBitcoins.com](http://www.localbitcoins.com). They have designed the website to facilitate cash transactions via an escrow service. You can also see people buying and selling Bitcoin using cash, based on their location, in which you can filter those nearby. I would recommend doing a couple of bank transfers exchanges on the site first so you get a feel for the escrow service and you can also build up a little reputaion to build trust.


---

### Answer by username_7 on 2018-02-27. Score: 0

If a bitcoin address is the recipient of 1000 BTC (it is a utxo), and you send 0.00000001 BTC to someone, the transaction reveals the amount of bitcoin on that address, that address, the public key, and the remainder is sent back to the sender on a new address as change (minus transaction fees), a new address which has not revealed even its public keys yet, so no risk.

Many wallets will pick the smallest utxo to send from so if the wallet has received two transactions one for 1000 BTC, and one for 1 BTC and the wallet owner sends you 0.00000001 BTC then probably you will not be able to verify that they, in fact, have the 1000 BTC that they claim as the smaller utxo would be used.

<https://localbitcoins.com/> is the website I was thinking of on which may people directly trade Bitcoin.

As others have said, you need to make sure that the BTC transaction is well confirmed before considering it final.

You might also consider using an escrow service.


---

