| Code | Name | High | Low | Close | Volume | Change | |
| OAK | Oaks Hotels & Resorts Ltd | 0.4300 | 0.4300 | 0.4300 | 5,000 | 0.0000 |  | 0.00 | 6 |
| OBJ | OBJ Ltd | 0.0550 | 0.0480 | 0.0490 | 85,119,630 | 0.0070 |  | 12.50 | 8 |
| OBL | Oil Basins Ltd | 0.0140 | 0.0140 | 0.0140 | 0 | 0.0000 |  | 0.00 | 4 |
| OCE | Ocean Capital Ltd | 0.2600 | 0.2600 | 0.2600 | 0 | 0.0000 |  | 0.00 | 5 |
| OCL | Objective Corporation Ltd | 0.2650 | 0.2650 | 0.2650 | 0 | 0.0000 |  | 0.00 | 5 |
| OCP | Oceania Capital Partners Ltd | 2.530 | 2.500 | 2.530 | 11,140 | 0.030 |  | 1.17 | 6 |
| ODG | Odyssey Gaming Ltd | 0.0430 | 0.0430 | 0.0430 | 0 | 0.0000 |  | 0.00 | 5 |
| ODN | Odin Energy Ltd | 0.0200 | 0.0200 | 0.0200 | 0 | 0.0000 |  | 0.00 | 5 |
| ODY | Odyssey Energy Ltd | 0.0350 | 0.0350 | 0.0350 | 20,000 | 0.0000 |  | 0.00 | 7 |
| OEC | Orbital Corporation Ltd | 0.0410 | 0.0400 | 0.0410 | 297,471 | 0.0010 |  | 2.50 | 5 |
| OEL | Ottoman Energy Ltd | 0.1150 | 0.1100 | 0.1150 | 775,476 | 0.0000 |  | 0.00 | 7 |
| OEQ | Orion Equities Ltd | 0.5100 | 0.5100 | 0.5100 | 0 | 0.0000 |  | 0.00 | 7 |
| OEX | Oilex NL | 0.1150 | 0.0980 | 0.1100 | 4,544,947 | 0.0140 |  | 14.58 | 6 |
| OFG | Over Fifty Group Ltd | 0.6300 | 0.6200 | 0.6200 | 36,153 | 0.0100 |  | 1.59 | 4 |
| OGC | Oceanagold Corporation | 2.490 | 2.440 | 2.490 | 214,835 | 0.010 |  | 0.40 | 6 |
| OGL | Overseas & General Ltd (Malay CUFS) | 0.0700 | 0.0700 | 0.0700 | 20,000 | 0.0100 |  | 16.67 | 4 |
| OHL | Omnitech Holdings Ltd | 0.0010 | 0.0010 | 0.0010 | 0 | 0.0000 |  | 0.00 | 5 |
| OIL | Optiscan Imaging Ltd | 0.0700 | 0.0680 | 0.0680 | 42,869 | 0.0010 |  | 1.49 | 6 |
| OIP | Orion Petroleum Ltd | 0.0720 | 0.0680 | 0.0680 | 140,000 | 0.0000 |  | 0.00 | 5 |
| OKJ | Oakajee Corporation Ltd | 0.0000 | 0.0000 | 0.0000 | 0 | 0.0000 |  | 0.00 | 0 |
| OKN | Oakton Ltd | 3.300 | 3.200 | 3.200 | 20,385 | 0.130 |  | 3.90 | 6 |
| OKU | Oklo Uranium Ltd | 0.0540 | 0.0540 | 0.0540 | 0 | 0.0000 |  | 0.00 | 7 |
| OLE | Olea Australis Ltd | 0.0040 | 0.0040 | 0.0040 | 0 | 0.0000 |  | 0.00 | 5 |
| OLH | Oldfields Holdings Ltd | 0.2300 | 0.2300 | 0.2300 | 25,000 | 0.0100 |  | 4.17 | 4 |
| OMH | OM Holdings Ltd | 1.710 | 1.700 | 1.710 | 235,744 | 0.005 |  | 0.29 | 5 |
| OMI | Occupational & Medical Innovatns Ltd | 0.1450 | 0.1450 | 0.1450 | 0 | 0.0000 |  | 0.00 | 5 |
| ONC | Oncard International Ltd | 0.1200 | 0.1200 | 0.1200 | 5,000 | 0.0000 |  | 0.00 | 5 |
| ONQ | On Q Group Ltd | 0.0720 | 0.0720 | 0.0720 | 0 | 0.0000 |  | 0.00 | 4 |
| ONT | 1300 Smiles Ltd | 2.890 | 2.890 | 2.890 | 200 | 0.010 |  | 0.34 | 5 |
| OOH | Oohmedia Group Ltd | 0.1000 | 0.1000 | 0.1000 | 0 | 0.0000 |  | 0.00 | 7 |
| ORC | Orchid Capital Ltd | 0.0250 | 0.0250 | 0.0250 | 0 | 0.0000 |  | 0.00 | 5 |
| ORD | Ord River Resources Ltd | 0.0460 | 0.0440 | 0.0450 | 1,014,744 | 0.0010 |  | 2.17 | 7 |
| ORE | Orocobre Ltd | 2.380 | 2.330 | 2.340 | 145,222 | 0.040 |  | 1.68 | 6 |
| ORG | Origin Energy Ltd | 16.85 | 16.50 | 16.70 | 2,315,908 | 0.22 |  | 1.33 | 5 |
| ORH | Orient Resource Holdings Ltd | 0.0320 | 0.0310 | 0.0310 | 800,000 | 0.0000 |  | 0.00 | 7 |
| ORI | Orica Ltd | 26.73 | 26.34 | 26.37 | 460,795 | 0.13 |  | 0.49 | 4 |
| ORL | OrotonGroup Ltd | 6.820 | 6.600 | 6.630 | 29,180 | 0.190 |  | 2.79 | 6 |
| ORM | Orion Metals | 0.0850 | 0.0850 | 0.0850 | 7,790 | 0.0070 |  | 8.97 | 6 |
| ORN | Orion Gold NL | 0.0300 | 0.0280 | 0.0300 | 329,538 | 0.0010 |  | 3.45 | 5 |
| ORO | Oroya Mining Ltd | 0.0050 | 0.0050 | 0.0050 | 150,000 | 0.0000 |  | 0.00 | 5 |
| ORT | ORT Ltd | 0.0140 | 0.0140 | 0.0140 | 0 | 0.0000 |  | 0.00 | 4 |
| OSH | Oil Search Ltd (PNG) | 5.880 | 5.800 | 5.850 | 10,510,030 | 0.050 |  | 0.85 | 5 |
| OST | Onesteel Ltd | 4.000 | 3.850 | 3.860 | 7,730,288 | 0.060 |  | 1.53 | 6 |
| OTI | Oriental Technologies Investment Ltd | 0.0370 | 0.0370 | 0.0370 | 0 | 0.0000 |  | 0.00 | 5 |
| OUM | Outback Metals Ltd | 0.0370 | 0.0370 | 0.0370 | 0 | 0.0000 |  | 0.00 | 5 |
| OVR | Overland Resources Ltd | 0.0850 | 0.0770 | 0.0850 | 445,000 | 0.0050 |  | 6.25 | 6 |
| OXX | Octanex N.l. | 0.3600 | 0.3600 | 0.3600 | 0 | 0.0000 |  | 0.00 | 6 |
| OXXO | Octanex N.l. | 0.1200 | 0.1200 | 0.1200 | 0 | 0.0000 |  | 0.00 | 5 |
| OYM | Olympus Pacific Minerals Inc | 0.2800 | 0.2800 | 0.2800 | 19,000 | 0.0000 |  | 0.00 | 4 |
| OZB | Oz Brewing Ltd | 0.0330 | 0.0330 | 0.0330 | 0 | 0.0000 |  | 0.00 | 4 |
| OZG | Ozgrowth Ltd | 0.1600 | 0.1600 | 0.1600 | 200,000 | 0.0000 |  | 0.00 | 6 |
| OZL | OZ Minerals Limited | 1.155 | 1.140 | 1.145 | 9,680,970 | 0.020 |  | 1.72 | 4 |