diff --git a/cmd/trader/data/args.go b/cmd/trader/data/args.go
index d78fe76..8eaec08 100644
--- a/cmd/trader/data/args.go
+++ b/cmd/trader/data/args.go
@@ -65,17 +65,21 @@ type datasetArgFlags struct {
 // addDatasetArgFlags registers --from, --to (both required), --format
 // (issue #111; defaults to "table"), and --exchange/--kind (issue
 // #331; required only for a non-FX provider) on cmd.
-func addDatasetArgFlags(cmd *cobra.Command, flags *datasetArgFlags) {
+func addDatasetConversionFlags(cmd *cobra.Command, flags *datasetArgFlags) {
 	cmd.Flags().StringVar(&flags.from, "from", "", "range start (YYYY-MM-DD or RFC3339), required")
 	cmd.Flags().StringVar(&flags.to, "to", "", "range end (YYYY-MM-DD or RFC3339), required")
-	cmd.Flags().StringVar(&flags.format, "format", formatTable,
-		"output format: "+formatTable+" or "+formatJSON)
 	cmd.Flags().StringVar(&flags.exchange, "exchange", "",
 		"listing exchange (for example ARCA or NASDAQ); required for a non-FX provider such as alpaca")
 	cmd.Flags().StringVar(&flags.kind, "kind", "",
 		`instrument kind, "equity" or "etf"; required for a non-FX provider such as alpaca`)
 }
 
+func addDatasetArgFlags(cmd *cobra.Command, flags *datasetArgFlags) {
+	addDatasetConversionFlags(cmd, flags)
+	cmd.Flags().StringVar(&flags.format, "format", formatTable,
+		"output format: "+formatTable+" or "+formatJSON)
+}
+
 // fxProviders names the providers whose bare INSTRUMENT argument is a
 // 6-letter FX pair symbol, resolved via svc.RegisterFXInstrument.
 // "oanda" is Trader's only FX provider today; every other configured
diff --git a/cmd/trader/data/command.go b/cmd/trader/data/command.go
index 0d4390f..a12d6b7 100644
--- a/cmd/trader/data/command.go
+++ b/cmd/trader/data/command.go
@@ -63,6 +63,7 @@ func New() *cobra.Command {
 	cmd.AddCommand(newSyncCmd())
 	cmd.AddCommand(newBuildCmd())
 	cmd.AddCommand(newUpdateCmd())
+	cmd.AddCommand(newConvertCmd())
 
 	return cmd
 }
diff --git a/cmd/trader/data/convert.go b/cmd/trader/data/convert.go
new file mode 100644
index 0000000..762d03f
--- /dev/null
+++ b/cmd/trader/data/convert.go
@@ -0,0 +1,112 @@
+package data
+
+import (
+	"archive/zip"
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/spf13/cobra"
+
+	svc "github.com/rustyeddy/trader/internal/service/marketdata"
+)
+
+// newConvertCmd imports one native Stooq archive member into managed raw
+// partitions and builds the requested canonical range. Extraction is always
+// temporary; the original ZIP remains the source of truth.
+func newConvertCmd() *cobra.Command {
+	var flags datasetArgFlags
+	var archivePath string
+
+	cmd := &cobra.Command{
+		Use:   "convert INSTRUMENT INTERVAL",
+		Short: "Convert one downloaded provider archive into canonical data.",
+		Args:  cobra.ExactArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			if archivePath == "" {
+				return fmt.Errorf("--archive is required")
+			}
+			dc, ok := dataContextFrom(cmd.Context())
+			if !ok {
+				return fmt.Errorf("data service is not configured on this command's context")
+			}
+			if strings.ToLower(dc.Provider) != "stooq" {
+				return fmt.Errorf("convert currently supports only provider stooq")
+			}
+			req, err := resolveDatasetRequest(cmd, args, flags)
+			if err != nil {
+				return err
+			}
+			if strings.ToUpper(args[1]) != "D1" {
+				return fmt.Errorf("stooq conversion currently supports only D1")
+			}
+			tmp, err := os.MkdirTemp("", "trader-stooq-convert-")
+			if err != nil {
+				return fmt.Errorf("create temporary extraction directory: %w", err)
+			}
+			defer func() { _ = os.RemoveAll(tmp) }()
+			extracted, err := extractStooqMember(cmd.Context(), archivePath, args[0], tmp)
+			if err != nil {
+				return err
+			}
+			resp, err := dc.Service.Convert(cmd.Context(), svc.ConvertRequest{
+				DatasetRequest: req, ArchivePath: extracted,
+			})
+			if err != nil {
+				return err
+			}
+			if _, err := fmt.Fprintf(cmd.OutOrStdout(), "imported %d rows across %d raw months; published %d canonical partitions\n",
+				resp.Import.RowsImported, resp.Import.MonthsWritten, len(resp.Build.Result.Published)); err != nil {
+				return err
+			}
+			return nil
+		},
+	}
+	cmd.Flags().StringVar(&archivePath, "archive", "", "native Stooq ZIP archive path")
+	addDatasetConversionFlags(cmd, &flags)
+	return cmd
+}
+
+func extractStooqMember(ctx context.Context, archivePath, symbol, destination string) (string, error) {
+	zr, err := zip.OpenReader(archivePath)
+	if err != nil {
+		return "", fmt.Errorf("open archive: %w", err)
+	}
+	defer func() { _ = zr.Close() }()
+	want := strings.ToLower(strings.TrimSpace(symbol)) + ".us.txt"
+	for _, entry := range zr.File {
+		if ctx.Err() != nil {
+			return "", ctx.Err()
+		}
+		if strings.ToLower(filepath.Base(entry.Name)) != want {
+			continue
+		}
+		if entry.FileInfo().IsDir() {
+			continue
+		}
+		in, err := entry.Open()
+		if err != nil {
+			return "", fmt.Errorf("open archive member %q: %w", entry.Name, err)
+		}
+		path := filepath.Join(destination, filepath.Base(entry.Name))
+		out, err := os.Create(path)
+		if err != nil {
+			_ = in.Close()
+			return "", fmt.Errorf("create extracted archive member: %w", err)
+		}
+		_, copyErr := io.Copy(out, in)
+		closeInErr := in.Close()
+		closeOutErr := out.Close()
+		if copyErr != nil {
+			return "", fmt.Errorf("extract archive member %q: %w", entry.Name, copyErr)
+		}
+		if closeInErr != nil || closeOutErr != nil {
+			return "", fmt.Errorf("close extracted archive member %q: %v %v", entry.Name, closeInErr, closeOutErr)
+		}
+		return path, nil
+	}
+	return "", fmt.Errorf("archive %q contains no %s member", archivePath, want)
+}
diff --git a/cmd/trader/data/convert_integration_test.go b/cmd/trader/data/convert_integration_test.go
new file mode 100644
index 0000000..0716185
--- /dev/null
+++ b/cmd/trader/data/convert_integration_test.go
@@ -0,0 +1,52 @@
+package data_test
+
+import (
+	"archive/zip"
+	"crypto/sha256"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestDataConvertStooqZIPToCanonical(t *testing.T) {
+	archivePath := filepath.Join(t.TempDir(), "daily.zip")
+	content := []byte("<TICKER>,<PER>,<DATE>,<TIME>,<OPEN>,<HIGH>,<LOW>,<CLOSE>,<VOL>,<OPENINT>\n" +
+		"SPY.US,D,20200131,000000,100,101,99,100.5,1000,0\n" +
+		"SPY.US,D,20200203,000000,100.5,102,100,101.5,2000,0\n")
+	writeZIPMember(t, archivePath, "data/daily/us/nyse etfs/2/spy.us.txt", content)
+	before := sha256.Sum256(mustReadFile(t, archivePath))
+	rawRoot, storeRoot := t.TempDir(), t.TempDir()
+
+	out, err := runData(t, storeRoot, rawRoot,
+		"convert", "SPY", "D1", "--provider", "stooq", "--archive", archivePath,
+		"--exchange", "ARCA", "--kind", "etf", "--from", "2020-01-01", "--to", "2020-03-01")
+	require.NoError(t, err)
+	require.Contains(t, out, "imported 2 rows across 2 raw months; published 2 canonical partitions")
+	require.Equal(t, before, sha256.Sum256(mustReadFile(t, archivePath)))
+	require.FileExists(t, filepath.Join(rawRoot, "SPY", "2020", "01", "SPY-2020-01-d1.csv"))
+	canonical := filepath.Join(storeRoot, "stooq", "SPY", "2020", "01", "SPY-2020-01-d1.csv")
+	require.FileExists(t, canonical)
+	require.Contains(t, string(mustReadFile(t, canonical)), `"provider":"stooq"`)
+}
+
+func writeZIPMember(t *testing.T, path, name string, content []byte) {
+	t.Helper()
+	f, err := os.Create(path)
+	require.NoError(t, err)
+	zw := zip.NewWriter(f)
+	w, err := zw.Create(name)
+	require.NoError(t, err)
+	_, err = w.Write(content)
+	require.NoError(t, err)
+	require.NoError(t, zw.Close())
+	require.NoError(t, f.Close())
+}
+
+func mustReadFile(t *testing.T, path string) []byte {
+	t.Helper()
+	data, err := os.ReadFile(path)
+	require.NoError(t, err)
+	return data
+}
diff --git a/cmd/trader/data/convert_test.go b/cmd/trader/data/convert_test.go
new file mode 100644
index 0000000..4e1281f
--- /dev/null
+++ b/cmd/trader/data/convert_test.go
@@ -0,0 +1,45 @@
+package data
+
+import (
+	"archive/zip"
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestExtractStooqMember_SelectsSPYAndPreservesContent(t *testing.T) {
+	archivePath := filepath.Join(t.TempDir(), "daily.zip")
+	f, err := os.Create(archivePath)
+	require.NoError(t, err)
+	zw := zip.NewWriter(f)
+	w, err := zw.Create("data/daily/us/nyse etfs/2/spy.us.txt")
+	require.NoError(t, err)
+	_, err = w.Write([]byte("<TICKER>,<PER>\nSPY.US,D\n"))
+	require.NoError(t, err)
+	require.NoError(t, zw.Close())
+	require.NoError(t, f.Close())
+
+	destination := t.TempDir()
+	path, err := extractStooqMember(context.Background(), archivePath, "SPY", destination)
+	require.NoError(t, err)
+	contents, err := os.ReadFile(path)
+	require.NoError(t, err)
+	require.Equal(t, "<TICKER>,<PER>\nSPY.US,D\n", string(contents))
+}
+
+func TestExtractStooqMemberReportsMissingSymbol(t *testing.T) {
+	archivePath := filepath.Join(t.TempDir(), "daily.zip")
+	f, err := os.Create(archivePath)
+	require.NoError(t, err)
+	zw := zip.NewWriter(f)
+	_, err = zw.Create("data/daily/us/nyse etfs/2/qqq.us.txt")
+	require.NoError(t, err)
+	require.NoError(t, zw.Close())
+	require.NoError(t, f.Close())
+
+	_, err = extractStooqMember(context.Background(), archivePath, "SPY", t.TempDir())
+	require.ErrorContains(t, err, "contains no spy.us.txt member")
+}
diff --git a/internal/marketdata/convert.go b/internal/marketdata/convert.go
new file mode 100644
index 0000000..cc34343
--- /dev/null
+++ b/internal/marketdata/convert.go
@@ -0,0 +1,40 @@
+package marketdata
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/rustyeddy/trader/instrument"
+	"github.com/rustyeddy/trader/internal/marketdata/internal/provider/stooq"
+)
+
+// StooqImportResult summarizes a native Stooq archive import without
+// exposing provider-internal record types across the Manager boundary.
+type StooqImportResult struct {
+	MonthsWritten int
+	RowsImported  int
+	FirstDate     time.Time
+	LastDate      time.Time
+}
+
+// ImportStooqArchive imports one native Stooq archive file into the
+// manager's configured managed raw root. The caller owns archive extraction;
+// this method only adapts the source into Trader's existing raw partitions.
+func (m *Manager) ImportStooqArchive(ctx context.Context, path string, id instrument.ID) (StooqImportResult, error) {
+	if !m.configured() {
+		return StooqImportResult{}, fmt.Errorf("marketdata: Stooq archive import: %w: manager is not configured", ErrInvalidConfig)
+	}
+	if m.providerName != "stooq" {
+		return StooqImportResult{}, fmt.Errorf("marketdata: Stooq archive import requires provider stooq, got %q", m.providerName)
+	}
+	if m.rawRoot == "" {
+		return StooqImportResult{}, fmt.Errorf("marketdata: Stooq archive import requires a raw root")
+	}
+	listing, err := m.resolver.ResolveInstrument(id, m.providerName, "")
+	if err != nil {
+		return StooqImportResult{}, fmt.Errorf("marketdata: Stooq archive import: resolve listing: %w", err)
+	}
+	result, err := stooq.ImportArchive(ctx, path, m.rawRoot, listing.Symbol())
+	return StooqImportResult{MonthsWritten: result.MonthsWritten, RowsImported: result.RowsImported, FirstDate: result.FirstDate, LastDate: result.LastDate}, err
+}
diff --git a/internal/service/marketdata/convert.go b/internal/service/marketdata/convert.go
new file mode 100644
index 0000000..974c15a
--- /dev/null
+++ b/internal/service/marketdata/convert.go
@@ -0,0 +1,34 @@
+package marketdata
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+
+	"github.com/rustyeddy/trader/marketdata"
+)
+
+// Convert imports one already-downloaded provider archive and then builds
+// canonical data through the same Manager Plan/Build path used elsewhere.
+func (s *Service) Convert(ctx context.Context, req ConvertRequest) (resp ConvertResponse, err error) {
+	if err := req.Validate(); err != nil {
+		return ConvertResponse{}, err
+	}
+	if req.ArchivePath == "" {
+		return ConvertResponse{}, fmt.Errorf("%w: archive path is required", ErrInvalidRequest)
+	}
+	if req.Interval != marketdata.D1 {
+		return ConvertResponse{}, fmt.Errorf("%w: stooq conversion supports only D1", ErrInvalidRequest)
+	}
+	defer func() {
+		s.logOutcome(ctx, slog.LevelInfo, "convert completed", "convert failed", req.DatasetRequest, err,
+			"rows_imported", resp.Import.RowsImported, "published_partitions", len(resp.Build.Result.Published))
+	}()
+	imported, err := s.manager.ImportStooqArchive(ctx, req.ArchivePath, req.Instrument)
+	if err != nil {
+		return ConvertResponse{}, err
+	}
+	build, err := s.Build(ctx, BuildRequest{DatasetRequest: req.DatasetRequest})
+	resp = ConvertResponse{Import: imported, Build: build}
+	return resp, err
+}
diff --git a/internal/service/marketdata/convert_test.go b/internal/service/marketdata/convert_test.go
new file mode 100644
index 0000000..6b3d3be
--- /dev/null
+++ b/internal/service/marketdata/convert_test.go
@@ -0,0 +1,59 @@
+package marketdata_test
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/rustyeddy/trader/instrument"
+	"github.com/rustyeddy/trader/internal/clock"
+	marketruntime "github.com/rustyeddy/trader/internal/marketdata"
+	svc "github.com/rustyeddy/trader/internal/service/marketdata"
+	"github.com/rustyeddy/trader/marketdata"
+	"github.com/rustyeddy/trader/num"
+)
+
+func TestConvertImportsAndBuildsStooqArchive(t *testing.T) {
+	resolver := instrument.NewMemoryResolver()
+	id, err := svc.RegisterETFInstrument(resolver, svc.EquityRegistration{
+		Provider: "stooq", Exchange: "ARCA", Ticker: "SPY", Currency: num.MustParseCurrency("USD"),
+	})
+	require.NoError(t, err)
+	rawRoot, storeRoot := t.TempDir(), t.TempDir()
+	manager, err := marketruntime.New(marketruntime.Config{
+		Clock: clock.NewSimulated(time.Date(2020, 3, 1, 0, 0, 0, 0, time.UTC)), StoreRoot: storeRoot,
+		RawRoot: rawRoot, Resolver: resolver, ProviderName: "stooq",
+		Calendar: marketdata.NewUSEquityCalendar(marketdata.StandardUSEquityHolidays(2020)),
+	})
+	require.NoError(t, err)
+	service, err := svc.New(manager, nil)
+	require.NoError(t, err)
+	path := filepath.Join(t.TempDir(), "spy.us.txt")
+	require.NoError(t, os.WriteFile(path, []byte(
+		"<TICKER>,<PER>,<DATE>,<TIME>,<OPEN>,<HIGH>,<LOW>,<CLOSE>,<VOL>,<OPENINT>\n"+
+			"SPY.US,D,20200131,000000,100,101,99,100.5,1000,0\n"), 0o644))
+	span, err := marketdata.NewTimeRange(time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC), time.Date(2020, 2, 1, 0, 0, 0, 0, time.UTC))
+	require.NoError(t, err)
+
+	resp, err := service.Convert(context.Background(), svc.ConvertRequest{
+		DatasetRequest: svc.DatasetRequest{Instrument: id, Interval: marketdata.D1, Range: span}, ArchivePath: path,
+	})
+	require.NoError(t, err)
+	require.Equal(t, 1, resp.Import.RowsImported)
+	require.Len(t, resp.Build.Result.Published, 1)
+}
+
+func TestConvertRejectsNonDailyIntervalBeforeImport(t *testing.T) {
+	service := newTestService(t)
+	span, err := marketdata.NewTimeRange(time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC), time.Date(2020, 2, 1, 0, 0, 0, 0, time.UTC))
+	require.NoError(t, err)
+	_, err = service.Convert(context.Background(), svc.ConvertRequest{
+		DatasetRequest: svc.DatasetRequest{Instrument: instrument.ETFID("ARCA", "SPY"), Interval: marketdata.H1, Range: span}, ArchivePath: "unused",
+	})
+	require.ErrorIs(t, err, svc.ErrInvalidRequest)
+	require.ErrorContains(t, err, "supports only D1")
+}
diff --git a/internal/service/marketdata/request.go b/internal/service/marketdata/request.go
index 65c75ed..0cc992b 100644
--- a/internal/service/marketdata/request.go
+++ b/internal/service/marketdata/request.go
@@ -111,3 +111,10 @@ type BuildRequest struct {
 type UpdateRequest struct {
 	DatasetRequest
 }
+
+// ConvertRequest imports one provider-native archive and builds the requested
+// canonical dataset from the resulting managed raw partitions.
+type ConvertRequest struct {
+	DatasetRequest
+	ArchivePath string
+}
diff --git a/internal/service/marketdata/response.go b/internal/service/marketdata/response.go
index ba5da48..088874c 100644
--- a/internal/service/marketdata/response.go
+++ b/internal/service/marketdata/response.go
@@ -114,3 +114,9 @@ type UpdateResponse struct {
 	Build         BuildResponse
 	FinalPlan     marketruntime.Plan
 }
+
+// ConvertResponse reports the imported raw source and canonical build.
+type ConvertResponse struct {
+	Import marketruntime.StooqImportResult
+	Build  BuildResponse
+}