diff --git a/chain/market/fundmgr_test.go b/chain/market/fundmgr_test.go
new file mode 100644
index 000000000..49db12e45
--- /dev/null
+++ b/chain/market/fundmgr_test.go
@@ -0,0 +1,172 @@
+package market
+
+import (
+	"context"
+	"errors"
+	"math/rand"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/specs-actors/actors/abi"
+	"github.com/filecoin-project/specs-actors/actors/builtin"
+	"github.com/filecoin-project/specs-actors/actors/crypto"
+	tutils "github.com/filecoin-project/specs-actors/support/testing"
+
+	"github.com/filecoin-project/lotus/api"
+	"github.com/filecoin-project/lotus/chain/actors"
+	"github.com/filecoin-project/lotus/chain/types"
+)
+
+type fakeAPI struct {
+	returnedBalance    api.MarketBalance
+	returnedBalanceErr error
+	signature          crypto.Signature
+	receivedMessage    *types.Message
+	pushMessageErr     error
+}
+
+func (fapi *fakeAPI) StateMarketBalance(context.Context, address.Address, types.TipSetKey) (api.MarketBalance, error) {
+	return fapi.returnedBalance, fapi.returnedBalanceErr
+}
+
+func (fapi *fakeAPI) MpoolPushMessage(ctx context.Context, msg *types.Message) (*types.SignedMessage, error) {
+	fapi.receivedMessage = msg
+	return &types.SignedMessage{
+		Message:   *msg,
+		Signature: fapi.signature,
+	}, fapi.pushMessageErr
+}
+
+func addFundsMsg(toAdd abi.TokenAmount, addr address.Address, wallet address.Address) *types.Message {
+	params, _ := actors.SerializeParams(&addr)
+	return &types.Message{
+		To:     builtin.StorageMarketActorAddr,
+		From:   wallet,
+		Value:  toAdd,
+		Method: builtin.MethodsMarket.AddBalance,
+		Params: params,
+	}
+}
+
+type expectedResult struct {
+	addAmt    abi.TokenAmount
+	shouldAdd bool
+	err       error
+}
+
+func TestAddFunds(t *testing.T) {
+	ctx := context.Background()
+	testCases := map[string]struct {
+		returnedBalanceErr error
+		returnedBalance    api.MarketBalance
+		addAmounts         []abi.TokenAmount
+		pushMessageErr     error
+		expectedResults    []expectedResult
+	}{
+		"succeeds, trivial case": {
+			returnedBalance: api.MarketBalance{Escrow: abi.NewTokenAmount(0), Locked: abi.NewTokenAmount(0)},
+			addAmounts:      []abi.TokenAmount{abi.NewTokenAmount(100)},
+			expectedResults: []expectedResult{
+				{
+					addAmt:    abi.NewTokenAmount(100),
+					shouldAdd: true,
+					err:       nil,
+				},
+			},
+		},
+		"succeeds, money already present": {
+			returnedBalance: api.MarketBalance{Escrow: abi.NewTokenAmount(150), Locked: abi.NewTokenAmount(50)},
+			addAmounts:      []abi.TokenAmount{abi.NewTokenAmount(100)},
+			expectedResults: []expectedResult{
+				{
+					shouldAdd: false,
+					err:       nil,
+				},
+			},
+		},
+		"succeeds, multiple adds": {
+			returnedBalance: api.MarketBalance{Escrow: abi.NewTokenAmount(150), Locked: abi.NewTokenAmount(50)},
+			addAmounts:      []abi.TokenAmount{abi.NewTokenAmount(100), abi.NewTokenAmount(200), abi.NewTokenAmount(250), abi.NewTokenAmount(250)},
+			expectedResults: []expectedResult{
+				{
+					shouldAdd: false,
+					err:       nil,
+				},
+				{
+					addAmt:    abi.NewTokenAmount(100),
+					shouldAdd: true,
+					err:       nil,
+				},
+				{
+					addAmt:    abi.NewTokenAmount(50),
+					shouldAdd: true,
+					err:       nil,
+				},
+				{
+					shouldAdd: false,
+					err:       nil,
+				},
+			},
+		},
+		"error on market balance": {
+			returnedBalanceErr: errors.New("something went wrong"),
+			addAmounts:         []abi.TokenAmount{abi.NewTokenAmount(100)},
+			expectedResults: []expectedResult{
+				{
+					err: errors.New("something went wrong"),
+				},
+			},
+		},
+		"error on push message": {
+			returnedBalance: api.MarketBalance{Escrow: abi.NewTokenAmount(0), Locked: abi.NewTokenAmount(0)},
+			pushMessageErr:  errors.New("something went wrong"),
+			addAmounts:      []abi.TokenAmount{abi.NewTokenAmount(100)},
+			expectedResults: []expectedResult{
+				{
+					err: errors.New("something went wrong"),
+				},
+			},
+		},
+	}
+
+	for testCase, data := range testCases {
+		t.Run(testCase, func(t *testing.T) {
+			ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
+			defer cancel()
+			sig := make([]byte, 100)
+			_, err := rand.Read(sig)
+			require.NoError(t, err)
+			fapi := &fakeAPI{
+				returnedBalance:    data.returnedBalance,
+				returnedBalanceErr: data.returnedBalanceErr,
+				signature: crypto.Signature{
+					Type: crypto.SigTypeUnknown,
+					Data: sig,
+				},
+				pushMessageErr: data.pushMessageErr,
+			}
+			fundMgr := newFundMgr(fapi)
+			addr := tutils.NewIDAddr(t, uint64(rand.Uint32()))
+			wallet := tutils.NewIDAddr(t, uint64(rand.Uint32()))
+			for i, amount := range data.addAmounts {
+				fapi.receivedMessage = nil
+				_, err := fundMgr.EnsureAvailable(ctx, addr, wallet, amount)
+				expected := data.expectedResults[i]
+				if expected.err == nil {
+					require.NoError(t, err)
+					if expected.shouldAdd {
+						expectedMessage := addFundsMsg(expected.addAmt, addr, wallet)
+						require.Equal(t, expectedMessage, fapi.receivedMessage)
+					} else {
+						require.Nil(t, fapi.receivedMessage)
+					}
+				} else {
+					require.EqualError(t, err, expected.err.Error())
+				}
+			}
+		})
+	}
+}