diff --git a/lib/blockchain/coins.js b/lib/blockchain/coins.js
index f75c7b4f..cd18e75e 100644
--- a/lib/blockchain/coins.js
+++ b/lib/blockchain/coins.js
@@ -221,37 +221,24 @@ Coins.prototype.isEmpty = function isEmpty() {
 Coins.prototype.toRaw = function toRaw() {
   var bw = new BufferWriter();
   var len = this.outputs.length;
-  var first = len > 0 && this.outputs[0];
-  var second = len > 1 && this.outputs[1];
-  var size = 0;
-  var nonzero = 0;
+  var size = Math.floor((len + 5) / 8);
+  var first = this.has(0);
+  var second = this.has(1);
+  var offset = 0;
   var i, j, code, ch, output;
 
   // Throw if we're fully spent.
   assert(len !== 0, 'Cannot serialize fully-spent coins.');
 
-  // Calculate number of unspents and spent field size.
-  // size = number of bytes required for the bit field.
-  // nonzero = number of non-zero bytes required.
-  for (i = 0; 2 + i * 8 < len; i++) {
-    for (j = 0; j < 8 && 2 + i * 8 + j < len; j++) {
-      if (this.outputs[2 + i * 8 + j]) {
-        size = i + 1;
-        nonzero++;
-        break;
-      }
-    }
-  }
-
   // First and second bits
   // have a double meaning.
   if (!first && !second) {
-    assert(nonzero !== 0);
-    nonzero -= 1;
+    assert(size !== 0);
+    offset = 1;
   }
 
   // Calculate header code.
-  code = 8 * nonzero;
+  code = 8 * (size - offset);
 
   if (this.coinbase)
     code += 1;
@@ -300,8 +287,11 @@ Coins.prototype.toRaw = function toRaw() {
 
 Coins.prototype.fromRaw = function fromRaw(data, hash) {
   var br = new BufferReader(data);
-  var i, code, field, nonzero, ch, unspent, coin;
+  var first = null;
+  var second = null;
+  var i, j, code, size, offset, ch;
 
+  // Inject hash (passed by caller).
   this.hash = hash;
 
   // Read headers.
@@ -310,41 +300,36 @@ Coins.prototype.fromRaw = function fromRaw(data, hash) {
   code = br.readVarint();
   this.coinbase = (code & 1) !== 0;
 
-  // Setup spent field.
-  field = [
-    (code & 2) !== 0,
-    (code & 4) !== 0
-  ];
-
   // Recalculate number of non-zero bytes.
-  nonzero = code / 8 | 0;
+  size = code / 8 | 0;
 
   if ((code & 6) === 0)
-    nonzero += 1;
+    size += 1;
 
-  // Read spent field.
-  while (nonzero > 0) {
-    ch = br.readU8();
-    for (i = 0; i < 8; i++) {
-      unspent = (ch & (1 << i)) !== 0;
-      field.push(unspent);
-    }
-    if (ch !== 0)
-      nonzero--;
-  }
+  // Setup spent field.
+  offset = br.offset;
+  br.seek(size);
+
+  // Read first two outputs.
+  if ((code & 2) !== 0)
+    first = CoinEntry.fromReader(br);
+
+  if ((code & 4) !== 0)
+    second = CoinEntry.fromReader(br);
+
+  this.outputs.push(first);
+  this.outputs.push(second);
 
   // Read outputs.
-  for (i = 0; i < field.length; i++) {
-    if (!field[i]) {
-      this.outputs.push(null);
-      continue;
+  for (i = 0; i < size; i++) {
+    ch = br.data[offset++];
+    for (j = 0; j < 8; j++) {
+      if ((ch & (1 << j)) === 0) {
+        this.outputs.push(null);
+        continue;
+      }
+      this.outputs.push(CoinEntry.fromReader(br));
     }
-
-    // Store the offset and size
-    // in the compressed coin object.
-    coin = CoinEntry.fromReader(br);
-
-    this.outputs.push(coin);
   }
 
   this.cleanup();
@@ -363,8 +348,9 @@ Coins.prototype.fromRaw = function fromRaw(data, hash) {
 Coins.parseCoin = function parseCoin(data, hash, index) {
   var br = new BufferReader(data);
   var coin = new Coin();
-  var i, code, field, nonzero, ch, unspent;
+  var i, j, code, size, offset, ch;
 
+  // Inject outpoint (passed by caller).
   coin.hash = hash;
   coin.index = index;
 
@@ -374,56 +360,49 @@ Coins.parseCoin = function parseCoin(data, hash, index) {
   code = br.readVarint();
   coin.coinbase = (code & 1) !== 0;
 
-  // Setup spent field.
-  field = [
-    (code & 2) !== 0,
-    (code & 4) !== 0
-  ];
-
   // Recalculate number of non-zero bytes.
-  nonzero = code / 8 | 0;
+  size = code / 8 | 0;
 
   if ((code & 6) === 0)
-    nonzero += 1;
+    size += 1;
 
-  // Read spent field.
-  while (nonzero > 0 && field.length <= index) {
-    ch = br.readU8();
-    for (i = 0; i < 8; i++) {
-      unspent = (ch & (1 << i)) !== 0;
-      field.push(unspent);
-    }
-    if (ch !== 0)
-      nonzero--;
-  }
-
-  if (field.length <= index)
+  if (index >= 2 + size * 8)
     return;
 
-  while (nonzero > 0) {
-    if (br.readU8() !== 0)
-      nonzero--;
-  }
+  // Read spent field.
+  offset = br.offset;
+  br.seek(size);
 
-  // Read outputs.
-  for (i = 0; i < field.length; i++) {
-    if (i === index) {
-      if (!field[i])
+  for (i = 2; i <= 4; i += 2) {
+    if ((code & i) !== 0) {
+      if (index === 0) {
+        decompress.coin(coin, br);
+        return coin;
+      }
+      decompress.skip(br);
+    } else {
+      if (index === 0)
         return;
-
-      // Read compressed output.
-      decompress.coin(coin, br);
-
-      break;
     }
-
-    if (!field[i])
-      continue;
-
-    decompress.skip(br);
+    index -= 1;
   }
 
-  return coin;
+  for (i = 0; i < size; i++) {
+    ch = br.data[offset++];
+    for (j = 0; j < 8; j++) {
+      if ((ch & (1 << j)) !== 0) {
+        if (index === 0) {
+          decompress.coin(coin, br);
+          return coin;
+        }
+        decompress.skip(br);
+      } else {
+        if (index === 0)
+          return;
+      }
+      index -= 1;
+    }
+  }
 };
 
 /**