diff --git a/README.md b/README.md
index da082ab..5ca3e83 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,6 @@
 
 
 * ⬛️ **[blockchains 101](blockchains)**
-* ⬛️ **[ethereum](blockchains/ethereum)**
 * ⬛️ **[consensus](consensus)**
 * ⬛️ **[cryptoeconomics](cryptoeconomics)**
 * ⬛️ **[data availability](data_availability)**
diff --git a/blockchains/README.md b/blockchains/README.md
index 54af7e1..d2e33b1 100644
--- a/blockchains/README.md
+++ b/blockchains/README.md
@@ -2,8 +2,21 @@
 
 <br>
 
+### chapters
+
+<br>
+
+* **[ethereum](ethereum)**
+* **[bitcoin](bitcoin)**
+
+<br>
+
+---
+
 ### tl; dr
 
+<br>
+
 * **in general, blockchains have four core functions** (although modular blockchains specialize in one or two):
   * execution: transaction execution and state update.
   * settlement: finality and dispute resolution.
@@ -44,4 +57,3 @@
 * **[optimizing sparse merkle trees](https://ethresear.ch/t/optimizing-sparse-merkle-trees/3751)**
   
 
-
diff --git a/blockchains/bitcoin/README.md b/blockchains/bitcoin/README.md
new file mode 100644
index 0000000..457e5c0
--- /dev/null
+++ b/blockchains/bitcoin/README.md
@@ -0,0 +1,5 @@
+## cool bitcoin research
+
+<br>
+
+* **[scaling bitcoin for mass use, by e. ben-sasson](https://starkware.co/blog/scaling-bitcoin-for-mass-use/)**