diff --git a/README.md b/README.md
index e482467..62891b4 100644
--- a/README.md
+++ b/README.md
@@ -402,6 +402,23 @@ do not amend them.
 | `portfolio.positions(params?)` | Get trading positions |
 | `portfolio.activities(params?)` | Get activity history |
 
+Filter activity history by time and reward type:
+
+```python
+activities = client.portfolio.activities(
+    {
+        "startTime": "2026-10-01T00:00:00Z",
+        "endTime": "2026-10-02T00:00:00Z",
+        "types": ["ACTIVITY_TYPE_TAKER_FEE_REBATE", "ACTIVITY_TYPE_LIQUIDITY_PROGRAM"],
+    }
+)
+```
+
+Both time filters are optional RFC 3339 strings and include their endpoints.
+When supplied together, `startTime` must be before `endTime`. For later pages,
+pass `nextCursor` as `cursor` with the same filters until `eof` is true.
+The async client accepts the same parameters with `await`.
+
 ### Account (Authenticated)
 
 | Method | Description |
diff --git a/polymarket_us/types/portfolio.py b/polymarket_us/types/portfolio.py
index 7eabed6..7e1199e 100644
--- a/polymarket_us/types/portfolio.py
+++ b/polymarket_us/types/portfolio.py
@@ -14,6 +14,8 @@
     "ACTIVITY_TYPE_ACCOUNT_WITHDRAWAL",
     "ACTIVITY_TYPE_REFERRAL_BONUS",
     "ACTIVITY_TYPE_TRANSFER",
+    "ACTIVITY_TYPE_TAKER_FEE_REBATE",
+    "ACTIVITY_TYPE_LIQUIDITY_PROGRAM",
 ]
 
 SortOrder = Literal["SORT_ORDER_DESCENDING", "SORT_ORDER_ASCENDING"]
@@ -122,6 +124,8 @@ class GetActivitiesParams(TypedDict, total=False):
     marketSlug: str
     types: list[ActivityType]
     sortOrder: SortOrder
+    startTime: str
+    endTime: str
 
 
 class GetActivitiesResponse(TypedDict, total=False):
diff --git a/pyproject.toml b/pyproject.toml
index f66243f..48a8cdc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "polymarket-us"
-version = "2.4.1"
+version = "2.4.2"
 description = "Polymarket US Python SDK"
 readme = "README.md"
 license = "MIT"
diff --git a/tests/test_activity_history.py b/tests/test_activity_history.py
new file mode 100644
index 0000000..d755ca6
--- /dev/null
+++ b/tests/test_activity_history.py
@@ -0,0 +1,67 @@
+"""Activity filters pass through both clients without losing timestamp or type values."""
+
+from copy import deepcopy
+
+import pytest
+from pytest_httpx import HTTPXMock
+
+from polymarket_us import AsyncPolymarketUS, PolymarketUS
+from polymarket_us.types import GetActivitiesParams, GetActivitiesResponse
+from tests.types.activity_history import activities, params
+
+TEST_SECRET_KEY = "nWGxne/9WmC6hEr0kuwsxERJxWl7MmkZcDusAxyuf2A="
+
+QUERIES: list[GetActivitiesParams | None] = [
+    None,
+    {
+        "startTime": "2026-10-01T00:00:00.123456789Z",
+        "types": ["ACTIVITY_TYPE_TAKER_FEE_REBATE"],
+    },
+    {
+        "endTime": "2026-10-02T00:00:00.123456789+05:30",
+        "types": ["ACTIVITY_TYPE_LIQUIDITY_PROGRAM"],
+    },
+    params,
+]
+
+
+@pytest.mark.parametrize("asynchronous", [False, True], ids=["sync", "async"])
+@pytest.mark.parametrize("query", QUERIES, ids=["omitted", "start-only", "end-only", "combined"])
+async def test_activity_history_filters(
+    httpx_mock: HTTPXMock, asynchronous: bool, query: GetActivitiesParams | None
+) -> None:
+    response: GetActivitiesResponse = {
+        "activities": activities,
+        "nextCursor": "next+/=cursor",
+        "eof": False,
+    }
+    httpx_mock.add_response(json=response)
+    original_query = deepcopy(query)
+
+    if asynchronous:
+        async with AsyncPolymarketUS(
+            key_id="offline", secret_key=TEST_SECRET_KEY, api_base_url="https://api.test"
+        ) as client:
+            result = await client.portfolio.activities(query)
+    else:
+        with PolymarketUS(
+            key_id="offline", secret_key=TEST_SECRET_KEY, api_base_url="https://api.test"
+        ) as sync_client:
+            result = sync_client.portfolio.activities(query)
+
+    assert result == response
+    assert query == original_query
+    requests = httpx_mock.get_requests()
+    assert len(requests) == 1
+    request = requests[0]
+    assert request.method == "GET"
+    assert request.url.host == "api.test"
+    assert request.url.path == "/v1/portfolio/activities"
+    assert request.content == b""
+    assert request.headers["X-PM-Access-Key"] == "offline"
+    expected = original_query or {}
+    assert set(request.url.params) == set(expected)
+    for key, value in expected.items():
+        assert request.url.params.get_list(key) == (
+            value if isinstance(value, list) else [str(value)]
+        )
diff --git a/tests/types/activity_history.py b/tests/types/activity_history.py
new file mode 100644
index 0000000..d2c44a5
--- /dev/null
+++ b/tests/types/activity_history.py
@@ -0,0 +1,27 @@
+"""Typed consumers of activity time filters and reward categories."""
+
+from polymarket_us import AsyncPolymarketUS, PolymarketUS
+from polymarket_us.types import Activity, ActivityType, GetActivitiesParams, GetActivitiesResponse
+
+reward_types: list[ActivityType] = [
+    "ACTIVITY_TYPE_TAKER_FEE_REBATE",
+    "ACTIVITY_TYPE_LIQUIDITY_PROGRAM",
+]
+params: GetActivitiesParams = {
+    "startTime": "2026-10-01T00:00:00.123456789Z",
+    "endTime": "2026-10-02T00:00:00.123456789+00:00",
+    "types": reward_types,
+    "limit": 2,
+    "cursor": "opaque+/=cursor",
+    "marketSlug": "example-market",
+    "sortOrder": "SORT_ORDER_ASCENDING",
+}
+activities: list[Activity] = [{"type": value} for value in reward_types]
+
+
+def history(client: PolymarketUS) -> GetActivitiesResponse:
+    return client.portfolio.activities(params)
+
+
+async def async_history(client: AsyncPolymarketUS) -> GetActivitiesResponse:
+    return await client.portfolio.activities(params)