diff --git a/haskoin-store.cabal b/haskoin-store.cabal
--- a/haskoin-store.cabal
+++ b/haskoin-store.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: 043df4dcff9f6f17106efe3b4dba479d97f95d3bdf73257d09b201d42f0b7eb1
+-- hash: 94a788ac41a95009b99d7e4662d0189ae04d0c2d2dabe31b2810aae27363d291
 
 name:           haskoin-store
-version:        0.34.3
+version:        0.34.4
 synopsis:       Storage and index for Bitcoin and Bitcoin Cash
 description:    Please see the README on GitHub at <https://github.com/haskoin/haskoin-store#readme>
 category:       Bitcoin, Finance, Network
@@ -53,7 +53,7 @@
     , hashable >=1.3.0.0
     , haskoin-core >=0.13.6
     , haskoin-node >=0.14.1
-    , haskoin-store-data ==0.34.3
+    , haskoin-store-data ==0.34.4
     , hedis >=0.12.13
     , http-types >=0.12.3
     , monad-logger >=0.3.32
@@ -96,7 +96,7 @@
     , haskoin-core >=0.13.6
     , haskoin-node >=0.14.1
     , haskoin-store
-    , haskoin-store-data ==0.34.3
+    , haskoin-store-data ==0.34.4
     , monad-logger >=0.3.32
     , mtl >=2.2.2
     , nqe >=0.6.1
@@ -135,8 +135,8 @@
     , hashable >=1.3.0.0
     , haskoin-core >=0.13.6
     , haskoin-node >=0.14.1
-    , haskoin-store ==0.34.3
-    , haskoin-store-data ==0.34.3
+    , haskoin-store ==0.34.4
+    , haskoin-store-data ==0.34.4
     , hedis >=0.12.13
     , hspec >=2.7.1
     , http-types >=0.12.3
diff --git a/src/Haskoin/Store/Logic.hs b/src/Haskoin/Store/Logic.hs
--- a/src/Haskoin/Store/Logic.hs
+++ b/src/Haskoin/Store/Logic.hs
@@ -54,7 +54,8 @@
                                                 TxRef (..), UnixTime,
                                                 Unspent (..), confirmed)
 import           Haskoin.Store.Database.Writer (MemoryTx, WriterT, runTx)
-import           UnliftIO                      (Exception, MonadIO, liftIO)
+import           UnliftIO                      (Exception, MonadIO, async,
+                                                liftIO, wait)
 
 type MonadImport m =
     ( MonadError ImportException m
@@ -119,23 +120,29 @@
         Just _ -> return False
         Nothing -> do
             freeOutputs True True [tx]
-            preLoadMemory [tx]
+            preLoadMemory False [tx]
             rbf <- isRBF (MemRef w) tx
             checkNewTx tx
             runMonadMemory $ importTx (MemRef w) w rbf tx
             return True
 
-preLoadMemory :: MonadLoggerIO m => [Tx] -> WriterT m ()
-preLoadMemory txs = do
+preLoadMemory :: MonadLoggerIO m => Bool -> [Tx] -> WriterT m ()
+preLoadMemory as txs = do
     $(logDebugS) "BlockStore" "Pre-loading memory"
     ReaderT $ \r -> do
         l <- askLoggerIO
         liftIO (runLoggingT (runReaderT go r) l)
   where
-    go = do
-        mapM_ loadPrevOut (concatMap prevOuts txs)
-        mapM_ loadOutputBalances txs
-        runTx . setMempool =<< getMempool
+    go
+      | as = do
+            as1 <- mapM (async . loadPrevOut) (concatMap prevOuts txs)
+            as2 <- mapM (async . loadOutputBalances) txs
+            runTx . setMempool =<< getMempool
+            mapM_ wait $ as1 ++ as2
+      | otherwise = do
+            mapM_ loadPrevOut (concatMap prevOuts txs)
+            mapM_ loadOutputBalances txs
+            runTx . setMempool =<< getMempool
 
 bestBlockData :: MonadImport m => WriterT m BlockData
 bestBlockData = do
@@ -160,7 +167,7 @@
                 "Cannot revert non-head block: " <> blockHashToHex bh
             throwError BlockNotBest
     tds <- mapM getImportTxData (blockDataTxs bd)
-    preLoadMemory $ map txData tds
+    preLoadMemory True $ map txData tds
     runTx $ do
         setBest (prevBlock (blockDataHeader bd))
         insertBlock bd {blockDataMainChain = False}
@@ -188,7 +195,7 @@
 importOrConfirm :: MonadImport m => BlockNode -> [Tx] -> WriterT m ()
 importOrConfirm bn txs = do
     freeOutputs True False txs
-    preLoadMemory txs
+    preLoadMemory True txs
     mapM_ (uncurry action) (sortTxs txs)
   where
     br i = BlockRef {blockRefHeight = nodeHeight bn, blockRefPos = i}
@@ -514,7 +521,7 @@
                 "Deleting tx: " <> txHashToHex th
             getSpenders th >>= \case
                 m | I.null m -> do
-                        preLoadMemory [txData td]
+                        preLoadMemory False [txData td]
                         runTx $ commitDelTx td
                   | otherwise -> do
                         $(logErrorS) "BlockStore" $