diff --git a/CHANGELOG.md b/CHANGELOG.md
index c5fbb545706a..04c59a6667b4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -77,6 +77,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (server) [#25632](https://github.com/cosmos/cosmos-sdk/pull/25632) Add missing call to close the app on shutdown.
 * (server) [#25740](https://github.com/cosmos/cosmos-sdk/pull/25740) Add variadic `grpc.DialOption` parameter to `StartGrpcServer` for custom gRPC client connection options.
 * (blockstm) [#25765](https://github.com/cosmos/cosmos-sdk/pull/25765) Minor code readability improvement in block-stm.
+* (blockstm) [#25767](https://github.com/cosmos/cosmos-sdk/pull/25767) Optimize block-stm memory allocation using bitmap and sync.Map.
 
 ### Bug Fixes
 
diff --git a/blockstm/mvdata.go b/blockstm/mvdata.go
index 0f4395542fab..b466ee5d66f6 100644
--- a/blockstm/mvdata.go
+++ b/blockstm/mvdata.go
@@ -42,30 +42,32 @@ func NewGMVData[V any](isZero func(V) bool, valueLen func(V) int) *GMVData[V] {
 	}
 }
 
-// getTree returns `nil` if not found
-func (d *GMVData[V]) getTree(key Key) *tree.BTree[secondaryDataItem[V]] {
+// getStore returns `nil` if not found
+func (d *GMVData[V]) getStore(key Key) *SecondaryStore[V] {
 	outer, _ := d.Get(dataItem[V]{Key: key})
-	return outer.Tree
+	return outer.Store
 }
 
-// getTreeOrDefault set a new tree atomically if not found.
-func (d *GMVData[V]) getTreeOrDefault(key Key) *tree.BTree[secondaryDataItem[V]] {
-	return d.GetOrDefault(dataItem[V]{Key: key}, (*dataItem[V]).Init).Tree
+// getStoreOrDefault set a new tree atomically if not found.
+func (d *GMVData[V]) getStoreOrDefault(key Key) *SecondaryStore[V] {
+	return d.GetOrDefault(dataItem[V]{Key: key}, (*dataItem[V]).Init).Store
 }
 
 func (d *GMVData[V]) Write(key Key, value V, version TxnVersion) {
-	tree := d.getTreeOrDefault(key)
-	tree.Set(secondaryDataItem[V]{Index: version.Index, Incarnation: version.Incarnation, Value: value})
+	tree := d.getStoreOrDefault(key)
+	tree.Set(version.Index, secondaryDataItem[V]{Incarnation: version.Incarnation, Value: value})
 }
 
 func (d *GMVData[V]) WriteEstimate(key Key, txn TxnIndex) {
-	tree := d.getTreeOrDefault(key)
-	tree.Set(secondaryDataItem[V]{Index: txn, Estimate: true})
+	tree := d.getStoreOrDefault(key)
+	tree.Set(txn, secondaryDataItem[V]{Estimate: true})
 }
 
 func (d *GMVData[V]) Delete(key Key, txn TxnIndex) {
-	tree := d.getTreeOrDefault(key)
-	tree.Delete(secondaryDataItem[V]{Index: txn})
+	tree := d.getStore(key)
+	if tree != nil {
+		tree.Delete(txn)
+	}
 }
 
 // Read returns the value and the version of the value that's less than the given txn.
@@ -78,18 +80,18 @@ func (d *GMVData[V]) Read(key Key, txn TxnIndex) (V, TxnVersion, bool) {
 		return zero, InvalidTxnVersion, false
 	}
 
-	tree := d.getTree(key)
-	if tree == nil {
+	store := d.getStore(key)
+	if store == nil {
 		return zero, InvalidTxnVersion, false
 	}
 
 	// find the closest txn that's less than the given txn
-	item, ok := seekClosestTxn(tree, txn)
+	idx, item, ok := store.PreviousValue(txn)
 	if !ok {
 		return zero, InvalidTxnVersion, false
 	}
 
-	return item.Value, item.Version(), item.Estimate
+	return item.Value, TxnVersion{idx, item.Incarnation}, item.Estimate
 }
 
 func (d *GMVData[V]) Iterator(
@@ -168,12 +170,13 @@ func (d *GMVData[V]) Snapshot() (snapshot []GKVPair[V]) {
 
 func (d *GMVData[V]) SnapshotTo(cb func(Key, V) bool) {
 	d.Scan(func(outer dataItem[V]) bool {
-		item, ok := outer.Tree.Max()
+		item, ok := outer.Store.Max()
 		if !ok {
 			return true
 		}
 
 		if item.Estimate {
+			// should not happen, just to keep it complete
 			return true
 		}
 
@@ -200,13 +203,13 @@ type GKVPair[V any] struct {
 type KVPair = GKVPair[[]byte]
 
 type dataItem[V any] struct {
-	Key  Key
-	Tree *tree.BTree[secondaryDataItem[V]]
+	Key   Key
+	Store *SecondaryStore[V]
 }
 
 func (d *dataItem[V]) Init() {
-	if d.Tree == nil {
-		d.Tree = tree.NewBTree(secondaryLesser[V], InnerBTreeDegree)
+	if d.Store == nil {
+		d.Store = NewSecondaryStore[V]()
 	}
 }
 
@@ -215,23 +218,3 @@ var _ tree.KeyItem = dataItem[[]byte]{}
 func (item dataItem[V]) GetKey() []byte {
 	return item.Key
 }
-
-type secondaryDataItem[V any] struct {
-	Index       TxnIndex
-	Incarnation Incarnation
-	Value       V
-	Estimate    bool
-}
-
-func secondaryLesser[V any](a, b secondaryDataItem[V]) bool {
-	return a.Index < b.Index
-}
-
-func (item secondaryDataItem[V]) Version() TxnVersion {
-	return TxnVersion{Index: item.Index, Incarnation: item.Incarnation}
-}
-
-// seekClosestTxn returns the closest txn that's less than the given txn.
-func seekClosestTxn[V any](tree *tree.BTree[secondaryDataItem[V]], txn TxnIndex) (secondaryDataItem[V], bool) {
-	return tree.ReverseSeek(secondaryDataItem[V]{Index: txn - 1})
-}
diff --git a/blockstm/mviterator.go b/blockstm/mviterator.go
index ce2f2fdfcc37..56de941d4a6f 100644
--- a/blockstm/mviterator.go
+++ b/blockstm/mviterator.go
@@ -75,7 +75,7 @@ func (it *MVIterator[V]) ReadEstimateValue() bool {
 func (it *MVIterator[V]) resolveValue() {
 	inner := &it.BTreeIteratorG
 	for ; inner.Valid(); inner.Next() {
-		v, ok := it.resolveValueInner(inner.Item().Tree)
+		idx, v, ok := it.resolveValueInner(inner.Item().Store)
 		if !ok {
 			// abort the iterator
 			it.Invalidate()
@@ -84,11 +84,12 @@ func (it *MVIterator[V]) resolveValue() {
 			return
 		}
 		if v == nil {
+			// value not found
 			continue
 		}
 
 		it.value = v.Value
-		it.version = v.Version()
+		it.version = TxnVersion{idx, v.Incarnation}
 		if it.Executing() {
 			it.reads = append(it.reads, ReadDescriptor{
 				Key:     inner.Item().Key,
@@ -102,25 +103,25 @@ func (it *MVIterator[V]) resolveValue() {
 // resolveValueInner loop until we find a value that is not an estimate,
 // wait for dependency if gets an ESTIMATE.
 // returns:
-// - (nil, true) if the value is not found
-// - (nil, false) if the value is an estimate and we should fail the validation
-// - (v, true) if the value is found
-func (it *MVIterator[V]) resolveValueInner(tree *tree.BTree[secondaryDataItem[V]]) (*secondaryDataItem[V], bool) {
+// - (0, nil, true) if the value is not found
+// - (0, nil, false) if the value is an estimate and we should fail the validation
+// - (idx, v, true) if the value is found at idx
+func (it *MVIterator[V]) resolveValueInner(tree *SecondaryStore[V]) (TxnIndex, *secondaryDataItem[V], bool) {
 	for {
-		v, ok := seekClosestTxn(tree, it.txn)
+		idx, v, ok := tree.PreviousValue(it.txn)
 		if !ok {
-			return nil, true
+			return 0, nil, true
 		}
 
 		if v.Estimate {
 			if it.Executing() {
-				it.waitFn(v.Index)
+				it.waitFn(idx)
 				continue
 			}
 			// in validation mode, it should fail validation immediately
-			return nil, false
+			return 0, nil, false
 		}
 
-		return &v, true
+		return idx, &v, true
 	}
 }
diff --git a/blockstm/secondary_store.go b/blockstm/secondary_store.go
new file mode 100644
index 000000000000..93805b4822a3
--- /dev/null
+++ b/blockstm/secondary_store.go
@@ -0,0 +1,79 @@
+package blockstm
+
+import (
+	"sync"
+
+	"github.com/RoaringBitmap/roaring/v2"
+)
+
+type secondaryDataItem[V any] struct {
+	Incarnation Incarnation
+	Value       V
+	Estimate    bool
+}
+
+type SecondaryStore[V any] struct {
+	// mu only protects bitmap, we don't sychonize between bitmap and data,
+	// the reader can observe a version in bitmap but not in data, which is handled at reader side.
+	mu     sync.RWMutex
+	bitmap roaring.Bitmap
+
+	data sync.Map
+}
+
+func NewSecondaryStore[V any]() *SecondaryStore[V] {
+	return &SecondaryStore[V]{}
+}
+
+func (s *SecondaryStore[V]) Set(version TxnIndex, item secondaryDataItem[V]) {
+	s.mu.Lock()
+	s.bitmap.Add(uint32(version))
+	s.mu.Unlock()
+
+	s.data.Store(version, item)
+}
+
+func (s *SecondaryStore[V]) Delete(version TxnIndex) {
+	s.mu.Lock()
+	s.bitmap.Remove(uint32(version))
+	s.mu.Unlock()
+
+	s.data.Delete(version)
+}
+
+// PreviousValue returns the closest version that's less than the given version, exclusive.
+func (s *SecondaryStore[V]) PreviousValue(target TxnIndex) (TxnIndex, secondaryDataItem[V], bool) {
+	for target > 0 {
+		s.mu.RLock()
+		prev := s.bitmap.PreviousValue(uint32(target - 1))
+		s.mu.RUnlock()
+
+		if prev == -1 {
+			return 0, secondaryDataItem[V]{}, false
+		}
+
+		target = TxnIndex(prev)
+		value, ok := s.data.Load(target)
+		if ok {
+			return target, value.(secondaryDataItem[V]), true
+		}
+	}
+
+	return 0, secondaryDataItem[V]{}, false
+}
+
+// Max is only called at block commit time, no need to synchronize.
+func (s *SecondaryStore[V]) Max() (secondaryDataItem[V], bool) {
+	if s.bitmap.IsEmpty() {
+		return secondaryDataItem[V]{}, false
+	}
+
+	target := TxnIndex(s.bitmap.Maximum())
+
+	value, ok := s.data.Load(target)
+	if !ok {
+		return secondaryDataItem[V]{}, false
+	}
+
+	return value.(secondaryDataItem[V]), true
+}
diff --git a/blockstm/stm.go b/blockstm/stm.go
index 307494b357d7..e2b7a0ccb953 100644
--- a/blockstm/stm.go
+++ b/blockstm/stm.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"math"
 	"runtime"
 
 	"golang.org/x/sync/errgroup"
@@ -36,6 +37,10 @@ func ExecuteBlockWithEstimates(
 	estimates []MultiLocations, // txn -> multi-locations
 	txExecutor TxExecutor,
 ) error {
+	if blockSize > math.MaxUint32 {
+		return fmt.Errorf("block size overflows uint32: %d", blockSize)
+	}
+
 	if executors < 0 {
 		return fmt.Errorf("invalid number of executors: %d", executors)
 	}
diff --git a/go.mod b/go.mod
index b62e0acb9d68..9b60eb07bb2f 100644
--- a/go.mod
+++ b/go.mod
@@ -13,6 +13,7 @@ require (
 	cosmossdk.io/store v1.3.0-beta.0
 	cosmossdk.io/x/tx v0.14.0
 	github.com/99designs/keyring v1.2.1
+	github.com/RoaringBitmap/roaring/v2 v2.14.4
 	github.com/bgentry/speakeasy v0.2.0
 	github.com/bits-and-blooms/bitset v1.24.4
 	github.com/chzyer/readline v1.5.1
@@ -191,6 +192,7 @@ require (
 	github.com/mattn/go-colorable v0.1.14 // indirect
 	github.com/minio/highwayhash v1.0.3 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
+	github.com/mschoch/smat v0.2.0 // indirect
 	github.com/mtibben/percent v0.2.1 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/oasisprotocol/curve25519-voi v0.0.0-20230904125328-1f23a7beb09a // indirect
diff --git a/go.sum b/go.sum
index 90c72f8cec77..f18654f70b8b 100644
--- a/go.sum
+++ b/go.sum
@@ -68,6 +68,8 @@ github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERo
 github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5 h1:TngWCqHvy9oXAN6lEVMRuU21PR1EtLVZJmdB18Gu3Rw=
 github.com/Nvveen/Gotty v0.0.0-20120604004816-cd527374f1e5/go.mod h1:lmUJ/7eu/Q8D7ML55dXQrVaamCz2vxCfdQBasLZfHKk=
+github.com/RoaringBitmap/roaring/v2 v2.14.4 h1:4aKySrrg9G/5oRtJ3TrZLObVqxgQ9f1znCRBwEwjuVw=
+github.com/RoaringBitmap/roaring/v2 v2.14.4/go.mod h1:oMvV6omPWr+2ifRdeZvVJyaz+aoEUopyv5iH0u/+wbY=
 github.com/Shopify/sarama v1.19.0/go.mod h1:FVkBWblsNy7DGZRfXLU0O9RCGt5g3g3yEuWXgklEdEo=
 github.com/Shopify/toxiproxy v2.1.4+incompatible/go.mod h1:OXgGpZ6Cli1/URJOF1DMxUHB2q5Ap20/P/eIdh4G0pI=
 github.com/VividCortex/gohistogram v1.0.0 h1:6+hBz+qvs0JOrrNhhmR7lFxo5sINxBCGXrdtl/UvroE=
@@ -612,6 +614,8 @@ github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJ
 github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
+github.com/mschoch/smat v0.2.0 h1:8imxQsjDm8yFEAVBe7azKmKSgzSkZXDuKkSq9374khM=
+github.com/mschoch/smat v0.2.0/go.mod h1:kc9mz7DoBKqDyiRL7VZN8KvXQMWeTaVnttLRXOlotKw=
 github.com/mtibben/percent v0.2.1 h1:5gssi8Nqo8QU/r2pynCm+hBQHpkB/uNK7BJCFogWdzs=
 github.com/mtibben/percent v0.2.1/go.mod h1:KG9uO+SZkUp+VkRHsCdYQV3XSZrrSpR3O9ibNBTZrns=
 github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 h1:C3w9PqII01/Oq1c1nUAm88MOHcQC9l5mIlSMApZMrHA=