diff --git a/lib/bcoin/txdb.js b/lib/bcoin/txdb.js
index 58ba1bc4..63d3b9d1 100644
--- a/lib/bcoin/txdb.js
+++ b/lib/bcoin/txdb.js
@@ -63,6 +63,8 @@ function TXDB(db, options) {
   this.jobs = [];
   this.locker = new bcoin.locker(this);
 
+  this.coinCache = new bcoin.lru(10000, 1);
+
   // Try to optimize for up to 1m addresses.
   // We use a regular bloom filter here
   // because we never want members to
@@ -394,6 +396,8 @@ TXDB.prototype._add = function add(tx, map, callback, force) {
 
           batch.del('c/' + key);
 
+          self.coinCache.remove(key);
+
           return next();
         }
 
@@ -528,7 +532,12 @@ TXDB.prototype._add = function add(tx, map, callback, force) {
                 batch.put('C/' + id + '/' + key, DUMMY);
               }
 
-              batch.put('c/' + key, coin.toRaw());
+              coin = coin.toRaw();
+
+              batch.put('c/' + key, coin);
+
+              self.coinCache.set(key, coin);
+
               updated = true;
             }
 
@@ -759,6 +768,7 @@ TXDB.prototype._confirm = function _confirm(tx, map, callback, force) {
 
     utils.forEachSerial(tx.outputs, function(output, next, i) {
       var address = output.getHash('hex');
+      var key = hash + '/' + i;
 
       // Only update coins if this output is ours.
       if (!map.hasPaths(address))
@@ -772,8 +782,11 @@ TXDB.prototype._confirm = function _confirm(tx, map, callback, force) {
           return next();
 
         coin.height = tx.height;
+        coin = coin.toRaw();
 
-        batch.put('c/' + hash + '/' + i, coin.toRaw());
+        batch.put('c/' + key, coin);
+
+        self.coinCache.set(key, coin);
 
         next();
       });
@@ -864,7 +877,8 @@ TXDB.prototype.lazyRemove = function lazyRemove(tx, callback, force) {
 
 TXDB.prototype._remove = function remove(tx, map, callback, force) {
   var self = this;
-  var unlock, hash, batch, i, j, path, id, key, paths, address, input, output;
+  var unlock, hash, batch, i, j, path, id;
+  var key, paths, address, input, output, coin;
 
   unlock = this._lock(remove, [tx, map, callback], force);
 
@@ -926,9 +940,13 @@ TXDB.prototype._remove = function remove(tx, map, callback, force) {
         batch.put('C/' + id + '/' + key, DUMMY);
       }
 
-      batch.put('c/' + key, input.coin.toRaw());
+      coin = input.coin.toRaw();
+
+      batch.put('c/' + key, coin);
       batch.del('s/' + key);
       batch.del('o/' + key);
+
+      self.coinCache.set(key, coin);
     }
 
     for (i = 0; i < tx.outputs.length; i++) {
@@ -951,6 +969,8 @@ TXDB.prototype._remove = function remove(tx, map, callback, force) {
       }
 
       batch.del('c/' + key);
+
+      self.coinCache.remove(key);
     }
 
     batch.write(function(err) {
@@ -1049,6 +1069,7 @@ TXDB.prototype._unconfirm = function unconfirm(tx, map, callback, force) {
   }
 
   utils.forEachSerial(tx.outputs, function(output, next, i) {
+    var key = hash + '/' + i;
     self.getCoin(hash, i, function(err, coin) {
       if (err)
         return next(err);
@@ -1057,8 +1078,11 @@ TXDB.prototype._unconfirm = function unconfirm(tx, map, callback, force) {
         return next();
 
       coin.height = tx.height;
+      coin = coin.toRaw();
 
-      batch.put('c/' + hash + '/' + i, coin.toRaw());
+      batch.put('c/' + key, coin);
+
+      self.coinCache.set(key, coin);
 
       next();
     });
@@ -1550,10 +1574,25 @@ TXDB.prototype.hasTX = function hasTX(hash, callback) {
  */
 
 TXDB.prototype.getCoin = function getCoin(hash, index, callback) {
-  this.db.fetch('c/' + hash + '/' + index, function(data) {
+  var key = hash + '/' + index;
+  var coin = this.coinCache.get(key);
+
+  if (coin) {
+    try {
+      coin = bcoin.coin.fromRaw(coin);
+    } catch (e) {
+      return callback(e);
+    }
+    coin.hash = hash;
+    coin.index = index;
+    return callback(null, coin);
+  }
+
+  this.db.fetch('c/' + key, function(data) {
     var coin = bcoin.coin.fromRaw(data);
     coin.hash = hash;
     coin.index = index;
+    self.coinCache.set(key, data);
     return coin;
   }, callback);
 };
@@ -1565,7 +1604,12 @@ TXDB.prototype.getCoin = function getCoin(hash, index, callback) {
  */
 
 TXDB.prototype.hasCoin = function hasCoin(hash, index, callback) {
-  return this.db.has('c/' + hash + '/' + index, callback);
+  var key = hash + '/' + index;
+
+  if (this.coinCache.has(key))
+    return callback(null, true);
+
+  return this.db.has('c/' + key, callback);
 };
 
 /**
@@ -1578,28 +1622,59 @@ TXDB.prototype.getBalance = function getBalance(id, callback) {
   var self = this;
   var confirmed = 0;
   var unconfirmed = 0;
+  var key, coin;
 
   if (typeof id === 'function') {
     callback = id;
     id = null;
   }
 
+  function parse(data) {
+    var height = data.readUInt32LE(4, true);
+    var value = utils.read64N(data, 8);
+
+    assert(data.length >= 16);
+
+    if (height === 0x7fffffff)
+      unconfirmed += value;
+    else
+      confirmed += value;
+  }
+
   return this.getCoinHashes(id, function(err, hashes) {
     if (err)
       return callback(err);
 
     utils.forEachSerial(hashes, function(hash, next) {
-      self.db.fetch('c/' + hash[0] + '/' + hash[1], function(data, key) {
-        var height = data.readUInt32LE(4, true);
-        var value = utils.read64N(data, 8);
+      key = hash[0] + '/' + hash[1];
+      coin = self.coinCache.get(key);
 
-        assert(data.length >= 16);
+      if (coin) {
+        try {
+          parse(coin);
+        } catch (e) {
+          return next(e);
+        }
+        return next();
+      }
 
-        if (height === 0x7fffffff)
-          unconfirmed += value;
-        else
-          confirmed += value;
-      }, next);
+      self.db.get('c/' + key, function(err, data) {
+        if (err)
+          return next(err);
+
+        if (!data)
+          return next();
+
+        try {
+          parse(data);
+        } catch (e) {
+          return callback(e);
+        }
+
+        self.coinCache.set(key, data);
+
+        next();
+      });
     }, function(err) {
       if (err)
         return callback(err);
diff --git a/lib/bcoin/wallet.js b/lib/bcoin/wallet.js
index c94b9d09..c49d2657 100644
--- a/lib/bcoin/wallet.js
+++ b/lib/bcoin/wallet.js
@@ -157,7 +157,6 @@ Wallet.prototype.open = function open(callback) {
 
 /**
  * Close the wallet, unregister with the database.
- * @method
  * @param {Function} callback
  */
 
@@ -2421,7 +2420,7 @@ MasterKey.fromOptions = function fromOptions(options) {
  * Decrypt the key and set a timeout to destroy decrypted data.
  * @param {Buffer|String} passphrase - Zero this yourself.
  * @param {Number} [timeout=60000] timeout in ms.
- * @returns {HDPrivateKey}
+ * @param {Function} callback - Returns [Error, {@link HDPrivateKey}].
  */
 
 MasterKey.prototype.unlock = function _unlock(passphrase, timeout, callback) {
@@ -2515,6 +2514,7 @@ MasterKey.prototype.destroy = function destroy() {
 /**
  * Decrypt the key permanently.
  * @param {Buffer|String} passphrase - Zero this yourself.
+ * @param {Function} callback
  */
 
 MasterKey.prototype.decrypt = function decrypt(passphrase, callback) {
@@ -2559,6 +2559,7 @@ MasterKey.prototype.decrypt = function decrypt(passphrase, callback) {
 /**
  * Encrypt the key permanently.
  * @param {Buffer|String} passphrase - Zero this yourself.
+ * @param {Function} callback
  */
 
 MasterKey.prototype.encrypt = function encrypt(passphrase, callback) {