Bitcoin and Segwit2x

The bitcoin network will undergo a fork in November 16th that will result in two blockchains with their corresponding tokens.

BTCJam will only support the current blockchain and will continue to refer to it as Bitcoin after the fork. We ceased operations in May 25, 2017 and no new features will be added, as a result the other blockchain, referred as Segwit2x, will not be supported.

If you still has a balance in your account please withdraw it as soon as possible, BTCJam is not intended to be used as an online wallet and the website will be taken offline in July 1, 2018, more information can be found here.




Bitcoin Network & BTCJam

BTCJam will disable deposits and withdraws until the upcoming protocol changes take effect. In the case of two surviving blockchains we are going to support the blockchain with the most accumulated difficulty.

Deposits and withdraws will be suspended starting 11pm UTC July 31st and will be reinstated as soon as the protocol becomes safe to transact.

BTCJam has closed

BTCJam began with one mission: To provide people around the world with access to fair credit.

From 2012 to 2016 we have serviced more than 20,600 loans in 122 countries, totaling more than 64,000 Bitcoin loaned. We have helped thousands of people around the world and are proud that we changed lives for the better.

We firmly believe that programmatic money and cryptocurrencies are here to stay and that there is still room for innovation in this space. That said, we have made the difficult decision to close BTCJam. The regulatory challenges around Bitcoin and the difficulties we faced in introducing Bitcoin technology to poor communities around the world are simply beyond our capacity.

No new loans can be made from today onward, and if you have any Bitcoin stored with us, you have until July 1, 2018 to withdraw it.

All borrowers with active loans can keep repaying them normally. The repayment functionality will remain available until all the loans have reached their term and either been fully repaid or have defaulted. After that, the website will be reduced to a simpler version that will only allow the withdrawal of a remaining balance.

We extend sincere thanks to all our lenders, borrowers, collaborators, investors, and everyone who believed in our dream of working together to provide access to fair credit without borders. It’s a mission we still believe in.

Team BTCJam.

AutoInvest Users are Averaging 18% in Returns

On May 20th, we released AutoInvest, a feature that allows our investors to easily diversify their  investments into 100 loans or more. The member feedback has been positive on the ease of use and the functionality that is in place.  We created this feature because many of our power-users understood the need to diversify; however, going through the loan listings was cumbersome and time consuming.

We are happy to share the early results with you – which show the power of diversification and also the strong adoption of AutoInvest.

From the table above, you can see the correlation between a diversified investment strategy and positive returns. Today, those investors who commit to an AutoInvest plan and maintain the plan on an ongoing basis are realizing the best outcomes.  Over 97% of investors are seeing a positive return over 18% while there are over 1,800 active AutoInvest plans.

For those of you using the program, let us know your feedback on improvements you would like to see or what you like about it.  If you have not tried the feature as an investor – see what you are missing in terms of simplifying and diversifying your P2P loans.

Create an AutoInvest plan today.

Update: Delays within the Bitcoin Network

As we continue to monitor the situation with the Bitcoin Network, we know this has a real impact on our users. In order to help our borrowers deal with the delay in deposits and payments we have decided to make some adjustments:

Effective today, we will be waiving late fees & late payment penalties for payments that are made within 48 hours of the due payment date.

We will continue to monitor the situation and keep you updated on the progress of the Bitcoin Network.

If you’d like to read more about the ongoing issues with transactions you can here.

If you have any questions regarding this please reach us at

Thank you!

BTCjam now offers support in four languages!

BTCjam - multilanguage


Ola! Hola! Здравствуйте! Hello!

We are pleased to announce that BTCjam now has support in English, Russian, Spanish and Portuguese. Please feel free to reach out to us in your native language for any assistance!

Nós da BTCjam temos o prazer de anunciar que estaremos oferecendo suporte em Inglês, Russo, Espanhol e Português. Sintam-se a vontade de entrar em contato conosco no idioma que preferir!

Nosotros de la BTCjam estamos contentos en anunciar que ahora ofrecemos suporte en Ingles, Ruso, Español y Portugues. Por favor contacte nosotros en tu idioma de preferencia!

Мы рады сообщить, что теперь BTCjam предоставляет поддержку на английском, русском, испанском и португальском языках. Вы можете задавать нам свои вопросы на любом из этих языков.

If you have any questions or need help please reach us at

Keep Jammin’

BTCjam Presents AutoInvest – The Easiest Way to Grow Your Coins.

We are happy to announce our new feature AutoInvest – the simple and powerful investment tool that will allow you to invest into hundreds of loans with just three clicks.

How it works

AutoInvest plans instantly diversify an investment budget into select loans that meet an investor’s selected portfolio criteria. Investors will be able to create investment plans with as little as 1 BTC.

We offer three different allocation profiles to match the risk appetite of an individual investor. Each of them have an expected return that takes into account what the borrowers are paying and the expected loss for the whole basket of loans. 

As the name implies, this portfolio is for conservative investors.  This plan’s objective to minimize risk and only invests in A and B loans.

This plan invests in A, B, and C rated loan listings.

‘Getting aggressive‘ with your risk profile allows you to invest across all loan ratings (A, B, C, and D). Investors that are comfortable with a higher level of risk can select this plan.

In addition to the allocation profiles, for those who want to customize their portfolios, we offer advanced settings where types of index currencies, loan terms and number of investments can be specified.

 Once the plan details are confirmed, investors can kick back and relax while our system automatically invests into dozens of loans ensuring your portfolio is diversified. If the plan’s investment amount set was higher than the current balance, future deposits will be used until the plan amount is met. AutoInvest plans are indexed and can be reviewed and monitored throughout their lifecycle.

Why should you use AutoInvest?

It’s simple.
We believe in providing the easiest way for investors to use BTCjam. With AutoInvest all investors need to do is deposit Bitcoin, choose your plan and check the returns.

It’s fast.
AutoInvest is a quick tool that requires little to no maintenance, some Bitcoin, and just three clicks to make the plan.

It’s reliable.
With every allocation profile, we provide the expected APR per plan. Keeping investor’s  portfolios diversified, and their returns transparent and consistent.

Other Changes

Together with AutoInvest, we are now using Yield to represent the return potential for individual loans. We received feedback on the confusion of “expected loss” on individual loans so, we’ve simplified it. By showing the yield, details about the individual loan and the borrower, we are allowing the investor to make the decision of whether to invest in any individual loan. 

Here is the formula for Yield:


Grow your coins with AutoInvest today!

Or, get a loan starting at 6.7% APR.

Over 800 bitcoin loans serviced in Brazil thanks to BTCJam


Brazil has outshone many other countries in the number of bitcoin loans occurring within its borders. Second only to the United States, more than 800 bitcoin loans have been given to Brazilians because of the much lower interest than those on loans offered locally. The average local interest rate can be close to triple digits and is not uncommon to go to 200 percent, while BTCJam offers loans between 5% and 20%.

Bitcoinist, Deutsche Banker Starts New Bitcoin Exchange in Brazil

Understanding Bitcoin Transactions

Seven months ago I joined BTCJam as Lead Backend Engineer, and I must confess at the time my knowledge about bitcoin was very limited. All I knew was that it was a digital money people use to buy funny stuff, right?

For the past few months I have been reading and learning a lot, and although I am no expert yet, many people including my friends consider me to be a “bitcoin master.” Some of the question they always ask me are, “‘what are all that bitcoin transactions we see on’ ‘Why do I see a lot of addresses on the left side (inputs) and several others on the right side (outputs)?’ ‘Why is there a seemingly random transfer to a weird address along with the amount that I actually transferred?’ and  ‘What about the transactions where I see hundreds of addresses on the right side?'”

If you ever thought of these things and you are not quite sure what is happening, then you are in the right place! In this blogpost I will try to explain as smoothly as possible what my “google-fu” has enabled me to learn about the magical world of bitcoin transactions.

To begin, let’s say you are selling products using bitcoins. You give your receiving address (address-A1) to the buyer, and he sends you 0.1BTC for a funny hat he just bought. Later, he wants a funny dinosaur costume and sends you 0.2BTC for it. Then another customer buys a water gun, but since you want to keep track of who paid what, you create another address in your wallet (address-A2) and your customer sends 0.4BTC to this address.

By the end of the day, your wallet has a balance of 0.7BTC. That actually means you have three “unspent outputs” in your wallet: 0.1 + 0.2 BTC in address-A1 + 0.4 BTC in address-A2. Although all the bitcoins are yours, they are associated with different addresses.


So what’s this “unspent output” you are seeing? It means from the three transactions that were made, your addresses were the output addresses of the transactions and you have not used those bitcoins (or outputs) in other transactions.
Now let’s see what happens when you decide to transfer 0.45 BTC to your friend’s address-F1 :


Whoa! What was that? Why are there two inputs and two outputs in this transaction?
You always spend the “unspent outputs” – you can not simply subtract 0.45 from your wallet because the bitcoins are tied to the address they were sent to. Futhermore, you always spend the outputs as a whole – you can not break an unspent output into smaller pieces. What actually happens is that you send two of your unspent outputs (0.4 BTC that was in address-A2 and 0.1 BTC from address-A1) and then get back 0.05 BTC in form of “change” in a new automatically generated address (address-Ach). The outputs are, therefore, 0.45 to your friend’s address (address-F1) and 0.05 to yourself in the address-Ach.

Your balance is now 0.25 BTC (or you have a sum of 0.25 unspent output):


The thing is that most bitcoin clients, like bitcoin-qt, do not show the change addresses in their standard interface, which is somewhat misleading to the user. Trust me! They are there.

Sometimes you can get a nice, round one-address-to-one transaction if the amount you are sending happens to match any of your unspent outputs. In this case, if you happened to send 0.2 or 0.05 BTC to another address, you would spend a whole and single “unspent output” and no change would be needed.

This is what your transaction would look like:


Some of my friends often confused the “unspent outputs” with “unconfirmed transactions.” Remember that the unspent output is just BTC that is still sitting in one of you bitcoin addresses waiting to be used in the form of input in another transaction, while unconfirmed transactions are transactions that are not yet confirmed by the bitcoin network. On BTCJam, we use a minimum of 3 confirmations to make your bitcoins available for investment; this avoids exploits like transaction malleability.

Now, sometimes you are going to see things like this:

You might ask the same question I asked when I first saw it:

“Oh my! what is that!?”

It is now clear why there can only be a few inputs for a transaction: those addresses just happened to hold a sum of unspent outputs that are now inputs . But what about hundreds of outputs?

What happens is that transaction fees are incurred in the transaction. Let’s use a mining pool as an example that makes daily payments to its members and they can not afford to make one transaction to each member every day. You would spend a lot of bitcoin in transactions fees. In order to avoid this, they make use of a not very well know feature of the bitcoin protocol, which is sending different amounts of bitcoins to different addresses in a single transaction. With this you can minimize the transaction fees – and that is the reason you see sometimes those transactions with lots and lots of output addresses (remember that some of them might also be “change” addresses).

Some of you might ask “I got the whole ‘change address’ thing… but why? Why can’t they just send the change back to the input address? Wouldn’t that make this simpler to understand?”
Well… yes, it would. And that’s the point – Maybe you don’t want it to be simple. Look at this transaction.

Can you tell if the sender is spending 1.32492124 BTC and receiving 0.001 BTC back or if he is spending 0.001 BTC and receiving 1.32492124 BTC back as change? You can’t! And you can’t tell which address is the receiving address and which is the change address, improving, thus, one of the main bitcoin features: anonymity. You cannot just dig through all bitcoin transactions of address “abcdab” and see how much it has spent and how much the users balance is; after a few bitcoin transactions the balance is dispersed between several receive addresses and change addresses.

Well, that’s all folks. I hope I have helped some of you figure out this often confusing aspect of bitcoin. If you have more questions or comments, please don’t hesitate to write in our comments section! I’ll do my best to answer your questions right away – or figure out the answer ASAP!