diff --git a/box.c b/box.c
index d5f23b6..e96d8ec 100644
--- a/box.c
+++ b/box.c
@@ -73,7 +73,6 @@ draw_rectangle(double fx, double fy, double fwidth, double fheight)
 static void
 draw_chart(struct box *chart, double x, double y, double width, double height)
 {
-    char c = '@';
     long int actual_diff;
     double diff, price;
     enum ui_color color;
@@ -89,23 +88,11 @@ draw_chart(struct box *chart, double x, double y, double width, double height)
     actual_diff = 0;
 
     for (size_t i = 0; i < width; i++) {
-        diff = (double)rand() / RAND_MAX - 0.6;
-        actual_diff =  (size_t)(height + y - price)
-                       - (size_t)(height + y - (price + diff));
+        price = chart->chart->prices[i];
 
-        if (actual_diff > 0)  {
-            color = UI_GREEN;
-        } else if (actual_diff == 0) {
-            color = UI_NONE;
-        } else if (actual_diff < 0) {
-            color = UI_RED;
-        }
-
-        ui_color_on(color);
-        ui_char(x + i, height + y - price, c);
-        ui_color_off(color);
-
-        price += diff;
+        ui_color_on(UI_BLUE);
+        ui_char(x + i, height + y - price, '@');
+        ui_color_off(UI_BLUE);
     }
 }
 
@@ -163,16 +150,16 @@ draw_container(struct box *b, double x, double y, double width, double height)
 
 
 struct box *
-new_chart_box(void)
+new_chart_box(struct chart *chart)
 {
-    struct box *chart = malloc(sizeof(struct box));
+    struct box *box = malloc(sizeof(struct box));
 
-    chart->type = BOX_CHART;
-    chart->prices = emalloc(sizeof(double) * 100);
-    chart->fills = 1;
-    chart->color = UI_NONE;
+    box->type = BOX_CHART;
+    box->chart = chart;
+    box->fills = 1;
+    box->color = UI_NONE;
 
-    return chart;
+    return box;
 }
 
 
diff --git a/box.h b/box.h
index a0495c4..ca49bee 100644
--- a/box.h
+++ b/box.h
@@ -8,6 +8,7 @@
  
 #pragma once
 
+#include "chart.h"
 #include "ui.h"
 
 
@@ -27,18 +28,13 @@ struct box {
         /* button */
         char *name;
 
-        /* chart and vertical/horizontal box */
+        /* chart */
+        struct chart *chart;
+
+        /* vertical/horizontal  */
         struct {
-            /* chart and vertical/horizontal box */
             size_t length;
-
-            union {
-                /* vertical/horizontal box */
-                struct box **children;
-
-                /* chart */
-                double *prices;
-            };
+            struct box **children;
         };
     };
 };
@@ -47,7 +43,7 @@ struct box {
 struct box *new_button_box(char *name);
 struct box *new_vertical_box(void);
 struct box *new_horizontal_box(void);
-struct box *new_chart_box(void);
+struct box *new_chart_box(struct chart *);
 
 void append_box(struct box *parent, struct box *child);
 
diff --git a/chart.c b/chart.c
new file mode 100644
index 0000000..e1c6da0
--- /dev/null
+++ b/chart.c
@@ -0,0 +1,32 @@
+
+/*
+ * Copyright (C) Artsiom D.
+ * Copyright (C) shit-co.de
+ */
+
+
+#include <stdlib.h>
+#include "chart.h"
+#include "util.h"
+
+
+struct chart new_chart(unsigned int length)
+{
+    unsigned int  i;
+    double        price;
+    struct chart  chart;
+
+    chart.prices = emalloc(sizeof(double) * length);
+    chart.length = length;
+
+    /* populate with random prices */
+
+    price = 10;
+    
+    for (i = 0; i < length; i++) {
+        chart.prices[i] = price;
+        price += (double)rand() / RAND_MAX - 0.4;
+    }
+
+    return chart;
+}
diff --git a/chart.h b/chart.h
new file mode 100644
index 0000000..edc402c
--- /dev/null
+++ b/chart.h
@@ -0,0 +1,17 @@
+
+/*
+ * Copyright (C) Artsiom D.
+ * Copyright (C) shit-co.de
+ */
+
+ 
+#pragma once
+
+
+struct chart {
+    double *prices;     
+    unsigned int length;
+};
+
+
+struct chart new_chart(unsigned int length);
diff --git a/main.c b/main.c
index d299ba1..b1394c2 100644
--- a/main.c
+++ b/main.c
@@ -16,7 +16,9 @@
 int
 main(void)
 {
-    struct box *ui, *top, *bottom, *left, *right, *buy, *sell, *scam, *title, *desc;
+    struct box    *ui, *top, *bottom, *left, *right, *buy, *sell, *scam,
+                  *title, *desc;
+    struct chart   chart;
 
     ui_init();
 
@@ -27,7 +29,8 @@ main(void)
     append_box(top, title);
     append_box(top, desc);
 
-    left = new_chart_box();
+    chart = new_chart(400);
+    left = new_chart_box(&chart);
     left->fills = 5;
 
     buy = new_button_box("buy");
@@ -51,7 +54,7 @@ main(void)
     append_box(ui, top);
     append_box(ui, bottom);
 
-    draw_box(ui, 0, 0, ui_width()-1, ui_height()-1);
+    draw_box(ui, 0, 0, ui_width(), ui_height());
 
     ui_refresh();
     
diff --git a/makefile b/makefile
index 9c1a055..3e4e1f0 100644
--- a/makefile
+++ b/makefile
@@ -1,11 +1,12 @@
-CFLAGS = -std=c23 -Wextra -pedantic -Wall -pedantic
-LDFLAGS = -lncurses
+CFLAGS = -std=c23 -Wextra -pedantic -Wall -O0 -g3 -fsanitize=address
+LDFLAGS = -lncurses -fsanitize=address
 
-main: box.o main.o ui.o util.o
+main: box.o main.o ui.o util.o chart.o
 
 .PHONY: clean
 
 box.o: box.c
+chart.o: chart.c
 main.o: main.c
 ui.o: ui.c
 util.o: util.c
diff --git a/util.c b/util.c
index c3727b5..c0f6805 100644
--- a/util.c
+++ b/util.c
@@ -23,7 +23,7 @@ emalloc(size_t n)
 }
 
 
-void
+noreturn void
 die(char *fmt, ...)
 {
     va_list va;
diff --git a/util.h b/util.h
index d7f02bd..58c986e 100644
--- a/util.h
+++ b/util.h
@@ -8,7 +8,8 @@
 #pragma once
 
 #include <stddef.h>
+#include <stdnoreturn.h>
 
 
 void *emalloc(size_t n);
-void die(char *fmt, ...);
+noreturn void die(char *fmt, ...);