diff --git a/cmd/lotus-bench/amt_internal.go b/cmd/lotus-bench/amt_internal.go
new file mode 100644
index 000000000..892e4bf06
--- /dev/null
+++ b/cmd/lotus-bench/amt_internal.go
@@ -0,0 +1,309 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"math"
+	"sort"
+
+	cid "github.com/ipfs/go-cid"
+	cbg "github.com/whyrusleeping/cbor-gen"
+	xerrors "golang.org/x/xerrors"
+)
+
+type AMTRoot struct {
+	BitWidth uint64
+	Height   uint64
+	Count    uint64
+	AMTNode  AMTNode
+}
+
+type AMTNode struct {
+	Bmap   []byte
+	Links  []cid.Cid
+	Values []*cbg.Deferred
+}
+
+// Code generated by github.com/whyrusleeping/cbor-gen. DO NOT EDIT.
+
+var _ = xerrors.Errorf
+var _ = cid.Undef
+var _ = math.E
+var _ = sort.Sort
+
+var lengthBufAMTRoot = []byte{132}
+
+func (t *AMTRoot) MarshalCBOR(w io.Writer) error {
+	if t == nil {
+		_, err := w.Write(cbg.CborNull)
+		return err
+	}
+
+	cw := cbg.NewCborWriter(w)
+
+	if _, err := cw.Write(lengthBufAMTRoot); err != nil {
+		return err
+	}
+
+	// t.BitWidth (uint64) (uint64)
+
+	if err := cw.WriteMajorTypeHeader(cbg.MajUnsignedInt, uint64(t.BitWidth)); err != nil {
+		return err
+	}
+
+	// t.Height (uint64) (uint64)
+
+	if err := cw.WriteMajorTypeHeader(cbg.MajUnsignedInt, uint64(t.Height)); err != nil {
+		return err
+	}
+
+	// t.Count (uint64) (uint64)
+
+	if err := cw.WriteMajorTypeHeader(cbg.MajUnsignedInt, uint64(t.Count)); err != nil {
+		return err
+	}
+
+	// t.AMTNode (internal.AMTNode) (struct)
+	if err := t.AMTNode.MarshalCBOR(cw); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (t *AMTRoot) UnmarshalCBOR(r io.Reader) (err error) {
+	*t = AMTRoot{}
+
+	cr := cbg.NewCborReader(r)
+
+	maj, extra, err := cr.ReadHeader()
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+	}()
+
+	if maj != cbg.MajArray {
+		return fmt.Errorf("cbor input should be of type array")
+	}
+
+	if extra != 4 {
+		return fmt.Errorf("cbor input had wrong number of fields")
+	}
+
+	// t.BitWidth (uint64) (uint64)
+
+	{
+
+		maj, extra, err = cr.ReadHeader()
+		if err != nil {
+			return err
+		}
+		if maj != cbg.MajUnsignedInt {
+			return fmt.Errorf("wrong type for uint64 field")
+		}
+		t.BitWidth = uint64(extra)
+
+	}
+	// t.Height (uint64) (uint64)
+
+	{
+
+		maj, extra, err = cr.ReadHeader()
+		if err != nil {
+			return err
+		}
+		if maj != cbg.MajUnsignedInt {
+			return fmt.Errorf("wrong type for uint64 field")
+		}
+		t.Height = uint64(extra)
+
+	}
+	// t.Count (uint64) (uint64)
+
+	{
+
+		maj, extra, err = cr.ReadHeader()
+		if err != nil {
+			return err
+		}
+		if maj != cbg.MajUnsignedInt {
+			return fmt.Errorf("wrong type for uint64 field")
+		}
+		t.Count = uint64(extra)
+
+	}
+	// t.AMTNode (internal.AMTNode) (struct)
+
+	{
+
+		if err := t.AMTNode.UnmarshalCBOR(cr); err != nil {
+			return xerrors.Errorf("unmarshaling t.AMTNode: %w", err)
+		}
+
+	}
+	return nil
+}
+
+var lengthBufAMTNode = []byte{131}
+
+func (t *AMTNode) MarshalCBOR(w io.Writer) error {
+	if t == nil {
+		_, err := w.Write(cbg.CborNull)
+		return err
+	}
+
+	cw := cbg.NewCborWriter(w)
+
+	if _, err := cw.Write(lengthBufAMTNode); err != nil {
+		return err
+	}
+
+	// t.Bmap ([]uint8) (slice)
+	if len(t.Bmap) > cbg.ByteArrayMaxLen {
+		return xerrors.Errorf("Byte array in field t.Bmap was too long")
+	}
+
+	if err := cw.WriteMajorTypeHeader(cbg.MajByteString, uint64(len(t.Bmap))); err != nil {
+		return err
+	}
+
+	if _, err := cw.Write(t.Bmap[:]); err != nil {
+		return err
+	}
+
+	// t.Links ([]cid.Cid) (slice)
+	if len(t.Links) > cbg.MaxLength {
+		return xerrors.Errorf("Slice value in field t.Links was too long")
+	}
+
+	if err := cw.WriteMajorTypeHeader(cbg.MajArray, uint64(len(t.Links))); err != nil {
+		return err
+	}
+	for _, v := range t.Links {
+		if err := cbg.WriteCid(w, v); err != nil {
+			return xerrors.Errorf("failed writing cid field t.Links: %w", err)
+		}
+	}
+
+	// t.Values ([]*typegen.Deferred) (slice)
+	if len(t.Values) > cbg.MaxLength {
+		return xerrors.Errorf("Slice value in field t.Values was too long")
+	}
+
+	if err := cw.WriteMajorTypeHeader(cbg.MajArray, uint64(len(t.Values))); err != nil {
+		return err
+	}
+	for _, v := range t.Values {
+		if err := v.MarshalCBOR(cw); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (t *AMTNode) UnmarshalCBOR(r io.Reader) (err error) {
+	*t = AMTNode{}
+
+	cr := cbg.NewCborReader(r)
+
+	maj, extra, err := cr.ReadHeader()
+	if err != nil {
+		return err
+	}
+	defer func() {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+	}()
+
+	if maj != cbg.MajArray {
+		return fmt.Errorf("cbor input should be of type array")
+	}
+
+	if extra != 3 {
+		return fmt.Errorf("cbor input had wrong number of fields")
+	}
+
+	// t.Bmap ([]uint8) (slice)
+
+	maj, extra, err = cr.ReadHeader()
+	if err != nil {
+		return err
+	}
+
+	if extra > cbg.ByteArrayMaxLen {
+		return fmt.Errorf("t.Bmap: byte array too large (%d)", extra)
+	}
+	if maj != cbg.MajByteString {
+		return fmt.Errorf("expected byte array")
+	}
+
+	if extra > 0 {
+		t.Bmap = make([]uint8, extra)
+	}
+
+	if _, err := io.ReadFull(cr, t.Bmap[:]); err != nil {
+		return err
+	}
+	// t.Links ([]cid.Cid) (slice)
+
+	maj, extra, err = cr.ReadHeader()
+	if err != nil {
+		return err
+	}
+
+	if extra > cbg.MaxLength {
+		return fmt.Errorf("t.Links: array too large (%d)", extra)
+	}
+
+	if maj != cbg.MajArray {
+		return fmt.Errorf("expected cbor array")
+	}
+
+	if extra > 0 {
+		t.Links = make([]cid.Cid, extra)
+	}
+
+	for i := 0; i < int(extra); i++ {
+
+		c, err := cbg.ReadCid(cr)
+		if err != nil {
+			return xerrors.Errorf("reading cid field t.Links failed: %w", err)
+		}
+		t.Links[i] = c
+	}
+
+	// t.Values ([]*typegen.Deferred) (slice)
+
+	maj, extra, err = cr.ReadHeader()
+	if err != nil {
+		return err
+	}
+
+	if extra > cbg.MaxLength {
+		return fmt.Errorf("t.Values: array too large (%d)", extra)
+	}
+
+	if maj != cbg.MajArray {
+		return fmt.Errorf("expected cbor array")
+	}
+
+	if extra > 0 {
+		t.Values = make([]*cbg.Deferred, extra)
+	}
+
+	for i := 0; i < int(extra); i++ {
+
+		var v cbg.Deferred
+		if err := v.UnmarshalCBOR(cr); err != nil {
+			return err
+		}
+
+		t.Values[i] = &v
+	}
+
+	return nil
+}
diff --git a/cmd/lotus-bench/main.go b/cmd/lotus-bench/main.go
index 6e7e274f2..623c95eab 100644
--- a/cmd/lotus-bench/main.go
+++ b/cmd/lotus-bench/main.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"fmt"
@@ -8,9 +9,14 @@ import (
 	"math/rand"
 	"os"
 	"path/filepath"
+	"sync"
 	"time"
 
 	"github.com/docker/go-units"
+	"github.com/ipfs/boxo/blockservice"
+	"github.com/ipfs/go-cid"
+	offline "github.com/ipfs/go-ipfs-exchange-offline"
+	format "github.com/ipfs/go-ipld-format"
 	logging "github.com/ipfs/go-log/v2"
 	"github.com/minio/blake2b-simd"
 	"github.com/mitchellh/go-homedir"
@@ -20,7 +26,13 @@ import (
 	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/go-paramfetch"
 	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/filecoin-project/go-state-types/builtin/v9/verifreg"
 	prooftypes "github.com/filecoin-project/go-state-types/proof"
+	"github.com/filecoin-project/lotus/blockstore"
+	"github.com/filecoin-project/lotus/chain/actors/builtin/market"
+	adt "github.com/filecoin-project/specs-actors/v6/actors/util/adt"
+	"github.com/ipfs/boxo/ipld/merkledag"
+	cbor "github.com/ipfs/go-ipld-cbor"
 
 	lapi "github.com/filecoin-project/lotus/api"
 	"github.com/filecoin-project/lotus/build"
@@ -104,6 +116,7 @@ func main() {
 		DisableSliceFlagSeparator: true,
 		Commands: []*cli.Command{
 			proveCmd,
+			amtBenchCmd,
 			sealBenchCmd,
 			simpleCmd,
 			importBenchCmd,
@@ -117,6 +130,202 @@ func main() {
 	}
 }
 
+type amtStatCollector struct {
+	ds   format.NodeGetter
+	walk func(format.Node) ([]*format.Link, error)
+
+	statsLk               sync.Mutex
+	totalAMTLinks         int
+	totalAMTValues        int
+	totalAMTLinkNodes     int
+	totalAMTValueNodes    int
+	totalAMTLinkNodeSize  int
+	totalAMTValueNodeSize int
+}
+
+func (asc *amtStatCollector) String() string {
+	asc.statsLk.Lock()
+	defer asc.statsLk.Unlock()
+
+	str := "\n------------\n"
+	str += fmt.Sprintf("Link Count: %d\n", asc.totalAMTLinks)
+	str += fmt.Sprintf("Value Count: %d\n", asc.totalAMTValues)
+	str += fmt.Sprintf("%d link nodes %d bytes\n", asc.totalAMTLinkNodes, asc.totalAMTLinkNodeSize)
+	str += fmt.Sprintf("%d value nodes %d bytes\n", asc.totalAMTValueNodes, asc.totalAMTValueNodeSize)
+	str += fmt.Sprintf("Total bytes: %d\n------------\n", asc.totalAMTLinkNodeSize+asc.totalAMTValueNodeSize)
+	return str
+}
+
+func (asc *amtStatCollector) record(ctx context.Context, nd format.Node) error {
+	size, err := nd.Size()
+	if err != nil {
+		return err
+	}
+
+	var node AMTNode
+	if err := node.UnmarshalCBOR(bytes.NewReader(nd.RawData())); err != nil {
+		// try to deserialize root
+		var root AMTRoot
+		if err := root.UnmarshalCBOR(bytes.NewReader(nd.RawData())); err != nil {
+			return err
+		}
+		node = root.AMTNode
+	}
+
+	asc.statsLk.Lock()
+	defer asc.statsLk.Unlock()
+
+	link := len(node.Links) > 0
+	value := len(node.Values) > 0
+
+	if link {
+		asc.totalAMTLinks += len(node.Links)
+		asc.totalAMTLinkNodes += 1
+		asc.totalAMTLinkNodeSize += int(size)
+	} else if value {
+		asc.totalAMTValues += len(node.Values)
+		asc.totalAMTValueNodes += 1
+		asc.totalAMTValueNodeSize += int(size)
+	} else {
+		return xerrors.Errorf("unexpected AMT node %x: neither link nor value", nd.RawData())
+	}
+
+	return nil
+}
+
+func (asc *amtStatCollector) walkLinks(ctx context.Context, c cid.Cid) ([]*format.Link, error) {
+	nd, err := asc.ds.Get(ctx, c)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := asc.record(ctx, nd); err != nil {
+		return nil, err
+	}
+
+	return asc.walk(nd)
+}
+
+func carWalkFunc(nd format.Node) (out []*format.Link, err error) {
+	for _, link := range nd.Links() {
+		if link.Cid.Prefix().Codec == cid.FilCommitmentSealed || link.Cid.Prefix().Codec == cid.FilCommitmentUnsealed {
+			continue
+		}
+		out = append(out, link)
+	}
+	return out, nil
+}
+
+var amtBenchCmd = &cli.Command{
+	Name:  "amt",
+	Usage: "Benchmark AMT churn",
+	Flags: []cli.Flag{
+		&cli.IntFlag{
+			Name:  "rounds",
+			Usage: "rounds of churn to measure",
+			Value: 1,
+		},
+		&cli.IntFlag{
+			Name:  "interval",
+			Usage: "AMT idx interval for churning values",
+			Value: 2880,
+		},
+	},
+	Action: func(c *cli.Context) error {
+		bs := blockstore.NewMemory()
+		ctx := c.Context
+		store := adt.WrapStore(ctx, cbor.NewCborStore(bs))
+
+		// Setup in memory blockstore
+		const bitwidth = 6
+		array, err := adt.MakeEmptyArray(store, bitwidth)
+		if err != nil {
+			return err
+		}
+
+		// Using motivating empirical example: market actor states AMT
+		// Create 40,000,000 states for realistic workload
+		fmt.Printf("Populating AMT\n")
+		for i := 0; i < 40000000; i++ {
+			array.Set(uint64(i), &market.DealState{
+				SectorStartEpoch: abi.ChainEpoch(2000000 + i),
+				LastUpdatedEpoch: abi.ChainEpoch(-1),
+				SlashEpoch:       -1,
+				VerifiedClaim:    verifreg.AllocationId(i),
+			})
+		}
+
+		r, err := array.Root()
+		if err != nil {
+			return err
+		}
+
+		// Measure ratio of internal / leaf nodes / sizes
+		dag := merkledag.NewDAGService(blockservice.New(bs, offline.Exchange(bs)))
+		asc := &amtStatCollector{
+			ds:   dag,
+			walk: carWalkFunc,
+		}
+
+		fmt.Printf("Measuring AMT\n")
+		seen := cid.NewSet()
+		if err := merkledag.Walk(ctx, asc.walkLinks, r, seen.Visit, merkledag.Concurrent()); err != nil {
+			return err
+		}
+
+		fmt.Printf("%s\n", asc)
+
+		// Overwrite ids with idx % interval: one epoch of market cron
+		rounds := c.Int("rounds")
+		interval := c.Int("interval")
+
+		fmt.Printf("Overwrite 1 out of %d values for %d rounds\n", interval, rounds)
+		array, err = adt.AsArray(store, r, bitwidth)
+		if err != nil {
+			return err
+		}
+		roots := make([]cid.Cid, rounds)
+		for j := 0; j < rounds; j++ {
+			if j%10 == 0 {
+				fmt.Printf("round: %d\n", j)
+			}
+			for i := j; i < 40000000; i += interval {
+				if i%interval == j {
+					array.Set(uint64(i), &market.DealState{
+						SectorStartEpoch: abi.ChainEpoch(2000000 + i),
+						LastUpdatedEpoch: abi.ChainEpoch(1),
+						SlashEpoch:       -1,
+						VerifiedClaim:    verifreg.AllocationId(i),
+					})
+				}
+			}
+			roots[j], err = array.Root()
+			if err != nil {
+				return err
+			}
+
+		}
+
+		// Measure churn
+		dag = merkledag.NewDAGService(blockservice.New(bs, offline.Exchange(bs)))
+		asc = &amtStatCollector{
+			ds:   dag,
+			walk: carWalkFunc,
+		}
+
+		fmt.Printf("Measuring %d rounds of churn\n", rounds)
+
+		for _, r := range roots {
+			if err := merkledag.Walk(ctx, asc.walkLinks, r, seen.Visit, merkledag.Concurrent()); err != nil {
+				return err
+			}
+		}
+
+		fmt.Printf("%s\n", asc)
+		return nil
+	},
+}
+
 var sealBenchCmd = &cli.Command{
 	Name:  "sealing",
 	Usage: "Benchmark seal and winning post and window post",
diff --git a/go.mod b/go.mod
index ab1f60b6e..fa17e9616 100644
--- a/go.mod
+++ b/go.mod
@@ -89,6 +89,7 @@ require (
 	github.com/ipfs/go-fs-lock v0.0.7
 	github.com/ipfs/go-graphsync v0.14.6
 	github.com/ipfs/go-ipfs-blocksutil v0.0.1
+	github.com/ipfs/go-ipfs-exchange-offline v0.3.0
 	github.com/ipfs/go-ipld-cbor v0.0.6
 	github.com/ipfs/go-ipld-format v0.5.0
 	github.com/ipfs/go-log/v2 v2.5.1
diff --git a/go.sum b/go.sum
index 71341203d..c5dc47a98 100644
--- a/go.sum
+++ b/go.sum
@@ -759,6 +759,7 @@ github.com/ipfs/go-ipfs-exchange-interface v0.2.0/go.mod h1:z6+RhJuDQbqKguVyslSO
 github.com/ipfs/go-ipfs-exchange-offline v0.0.1/go.mod h1:WhHSFCVYX36H/anEKQboAzpUws3x7UeEGkzQc3iNkM0=
 github.com/ipfs/go-ipfs-exchange-offline v0.1.1/go.mod h1:vTiBRIbzSwDD0OWm+i3xeT0mO7jG2cbJYatp3HPk5XY=
 github.com/ipfs/go-ipfs-exchange-offline v0.3.0 h1:c/Dg8GDPzixGd0MC8Jh6mjOwU57uYokgWRFidfvEkuA=
+github.com/ipfs/go-ipfs-exchange-offline v0.3.0/go.mod h1:MOdJ9DChbb5u37M1IcbrRB02e++Z7521fMxqCNRrz9s=
 github.com/ipfs/go-ipfs-files v0.0.3/go.mod h1:INEFm0LL2LWXBhNJ2PMIIb2w45hpXgPjNoE7yA8Y1d4=
 github.com/ipfs/go-ipfs-files v0.0.4/go.mod h1:INEFm0LL2LWXBhNJ2PMIIb2w45hpXgPjNoE7yA8Y1d4=
 github.com/ipfs/go-ipfs-files v0.3.0 h1:fallckyc5PYjuMEitPNrjRfpwl7YFt69heCOUhsbGxQ=