diff --git a/CHANGELOG.md b/CHANGELOG.md
index be0063fb05b..8e08d72de21 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,48 @@
 
 ## Unreleased
 
+### API
+
+* Ability to access version.properties API file with GraalVM native
+  ([#6095](https://github.com/open-telemetry/opentelemetry-java/pull/6095))
+
+### SDK
+
+#### Traces
+
+* Only call SpanProcessor onStart / onEnd if required
+  ([#6112](https://github.com/open-telemetry/opentelemetry-java/pull/6112))
+* Add option to export unsampled spans from span processors
+  ([#6057](https://github.com/open-telemetry/opentelemetry-java/pull/6057))
+
+#### Metrics
+
+* Memory Mode: Adding first part support for synchronous instruments - storage
+  ([#5998](https://github.com/open-telemetry/opentelemetry-java/pull/5998))
+* Base2ExponentialHistogramAggregation maxBuckets must be >= 2
+  ([#6093](https://github.com/open-telemetry/opentelemetry-java/pull/6093))
+* Convert histogram measurements to double before passing recording exemplar reservoir
+  ([#6024](https://github.com/open-telemetry/opentelemetry-java/pull/6024))
+
+#### Exporters
+
+* Add compressor SPI to support additional compression algos
+  ([#5990](https://github.com/open-telemetry/opentelemetry-java/pull/5990))
+* Test OTLP exporters with different OkHttp versions
+  ([#6045](https://github.com/open-telemetry/opentelemetry-java/pull/6045))
+* Refactor prometheus exporter to use `io.prometheus:prometheus-metrics-exporter-httpserver`, add
+  exponential Histogram support
+  ([#6015](https://github.com/open-telemetry/opentelemetry-java/pull/6015))
+* UpstreamGrpcSenderProvider uses minimal fallback managed channel when none is specified
+  ([#6110](https://github.com/open-telemetry/opentelemetry-java/pull/6110))
+* OTLP exporters propagate serialization IOException instead of rethrowing as runtime
+  ([#6082](https://github.com/open-telemetry/opentelemetry-java/pull/6082))
+
+#### Extensions
+
+* Autoconfigure reads normalized otel.config.file property
+  ([#6105](https://github.com/open-telemetry/opentelemetry-java/pull/6105))
+
 ## Version 1.33.0 (2023-12-08)
 
 ### API
diff --git a/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/BatchSpanProcessorBuilder.java b/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/BatchSpanProcessorBuilder.java
index 3e155bdfc5d..c3235a60f4f 100644
--- a/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/BatchSpanProcessorBuilder.java
+++ b/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/BatchSpanProcessorBuilder.java
@@ -25,7 +25,7 @@ public final class BatchSpanProcessorBuilder {
   static final int DEFAULT_EXPORT_TIMEOUT_MILLIS = 30_000;
 
   private final SpanExporter spanExporter;
-  private boolean exportUnsampledSpans;
+  private boolean exportUnsampledSpans = false;
   private long scheduleDelayNanos = TimeUnit.MILLISECONDS.toNanos(DEFAULT_SCHEDULE_DELAY_MILLIS);
   private int maxQueueSize = DEFAULT_MAX_QUEUE_SIZE;
   private int maxExportBatchSize = DEFAULT_MAX_EXPORT_BATCH_SIZE;
@@ -39,6 +39,8 @@ public final class BatchSpanProcessorBuilder {
   /**
    * Sets whether unsampled spans should be exported. If unset, defaults to exporting only sampled
    * spans.
+   *
+   * @since 1.34.0
    */
   public BatchSpanProcessorBuilder setExportUnsampledSpans(boolean exportUnsampledSpans) {
     this.exportUnsampledSpans = exportUnsampledSpans;
diff --git a/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/SimpleSpanProcessor.java b/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/SimpleSpanProcessor.java
index 3094b8645ca..432d7d056a0 100644
--- a/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/SimpleSpanProcessor.java
+++ b/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/SimpleSpanProcessor.java
@@ -56,6 +56,11 @@ public static SpanProcessor create(SpanExporter exporter) {
     return builder(exporter).build();
   }
 
+  /**
+   * Returns a new Builder for {@link SimpleSpanProcessor}.
+   *
+   * @since 1.34.0
+   */
   public static SimpleSpanProcessorBuilder builder(SpanExporter exporter) {
     requireNonNull(exporter, "exporter");
     return new SimpleSpanProcessorBuilder(exporter);
diff --git a/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/SimpleSpanProcessorBuilder.java b/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/SimpleSpanProcessorBuilder.java
index 76e5482cd9d..de9f3f9152a 100644
--- a/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/SimpleSpanProcessorBuilder.java
+++ b/sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/SimpleSpanProcessorBuilder.java
@@ -7,10 +7,14 @@
 
 import static java.util.Objects.requireNonNull;
 
-/** Builder class for {@link SimpleSpanProcessor}. */
+/**
+ * Builder class for {@link SimpleSpanProcessor}.
+ *
+ * @since 1.34.0
+ */
 public final class SimpleSpanProcessorBuilder {
   private final SpanExporter spanExporter;
-  private boolean exportUnsampledSpans;
+  private boolean exportUnsampledSpans = false;
 
   SimpleSpanProcessorBuilder(SpanExporter spanExporter) {
     this.spanExporter = requireNonNull(spanExporter, "spanExporter");