diff --git a/internal/storage/ledger/transactions.go b/internal/storage/ledger/transactions.go
index ac76a033f..60ba5ca0a 100644
--- a/internal/storage/ledger/transactions.go
+++ b/internal/storage/ledger/transactions.go
@@ -260,7 +260,7 @@ func (s *Store) CommitTransaction(ctx context.Context, tx *ledger.Transaction) e
 		}
 	}
 
-	postCommitVolumes, err := s.updateVolumes(ctx, volumeUpdates(tx)...)
+	postCommitVolumes, err := s.updateVolumes(ctx, tx.VolumeUpdates()...)
 	if err != nil {
 		return errors.Wrap(err, "failed to update balances")
 	}
@@ -559,46 +559,3 @@ func filterAccountAddressOnTransactions(address string, source, destination bool
 		return strings.Join(parts, " or ")
 	}
 }
-
-func volumeUpdates(transaction *ledger.Transaction) []ledger.AccountsVolumes {
-	aggregatedVolumes := make(map[string]map[string][]ledger.Posting)
-	for _, posting := range transaction.Postings {
-		if _, ok := aggregatedVolumes[posting.Source]; !ok {
-			aggregatedVolumes[posting.Source] = make(map[string][]ledger.Posting)
-		}
-		aggregatedVolumes[posting.Source][posting.Asset] = append(aggregatedVolumes[posting.Source][posting.Asset], posting)
-
-		if posting.Source == posting.Destination {
-			continue
-		}
-
-		if _, ok := aggregatedVolumes[posting.Destination]; !ok {
-			aggregatedVolumes[posting.Destination] = make(map[string][]ledger.Posting)
-		}
-		aggregatedVolumes[posting.Destination][posting.Asset] = append(aggregatedVolumes[posting.Destination][posting.Asset], posting)
-	}
-
-	ret := make([]ledger.AccountsVolumes, 0)
-	for account, movesByAsset := range aggregatedVolumes {
-		for asset, postings := range movesByAsset {
-			volumes := ledger.NewEmptyVolumes()
-			for _, posting := range postings {
-				if account == posting.Source {
-					volumes.Output.Add(volumes.Output, posting.Amount)
-				}
-				if account == posting.Destination {
-					volumes.Input.Add(volumes.Input, posting.Amount)
-				}
-			}
-
-			ret = append(ret, ledger.AccountsVolumes{
-				Account: account,
-				Asset:   asset,
-				Input:   volumes.Input,
-				Output:  volumes.Output,
-			})
-		}
-	}
-
-	return ret
-}
diff --git a/internal/transaction.go b/internal/transaction.go
index 923d506ed..129371d8c 100644
--- a/internal/transaction.go
+++ b/internal/transaction.go
@@ -110,6 +110,50 @@ func (tx Transaction) InvolvedAccounts() []string {
 	return slices.Compact(ret)
 }
 
+// todo: add unit tests!
+func (tx Transaction) VolumeUpdates() []AccountsVolumes {
+	aggregatedVolumes := make(map[string]map[string][]Posting)
+	for _, posting := range tx.Postings {
+		if _, ok := aggregatedVolumes[posting.Source]; !ok {
+			aggregatedVolumes[posting.Source] = make(map[string][]Posting)
+		}
+		aggregatedVolumes[posting.Source][posting.Asset] = append(aggregatedVolumes[posting.Source][posting.Asset], posting)
+
+		if posting.Source == posting.Destination {
+			continue
+		}
+
+		if _, ok := aggregatedVolumes[posting.Destination]; !ok {
+			aggregatedVolumes[posting.Destination] = make(map[string][]Posting)
+		}
+		aggregatedVolumes[posting.Destination][posting.Asset] = append(aggregatedVolumes[posting.Destination][posting.Asset], posting)
+	}
+
+	ret := make([]AccountsVolumes, 0)
+	for account, movesByAsset := range aggregatedVolumes {
+		for asset, postings := range movesByAsset {
+			volumes := NewEmptyVolumes()
+			for _, posting := range postings {
+				if account == posting.Source {
+					volumes.Output.Add(volumes.Output, posting.Amount)
+				}
+				if account == posting.Destination {
+					volumes.Input.Add(volumes.Input, posting.Amount)
+				}
+			}
+
+			ret = append(ret, AccountsVolumes{
+				Account: account,
+				Asset:   asset,
+				Input:   volumes.Input,
+				Output:  volumes.Output,
+			})
+		}
+	}
+
+	return ret
+}
+
 func (tx Transaction) MarshalJSON() ([]byte, error) {
 	type Aux Transaction
 	type Ret struct {