| OAP3 | Octopus Apollo Vct PLC | 46.30 | 46.30 | 46.30 | 0 | 0.00 | | 0.00 | |
| OAUE | UBS Etf | 42.76 | 42.76 | 42.76 | 11 | 0.00 | | 0.00 | |
| OBD | Oxford Biodynamics PLC | 0.2500 | 0.2250 | 0.2400 | 28.3M | -0.0100 | | 4.00 | |
| OBI | Ondine Biomedical Inc. | 10.500 | 9.525 | 9.750 | 568.1K | -0.500 | | 4.88 | |
| OCDO | Ocado Group PLC | 235.0 | 222.8 | 234.9 | 2.08M | 3.2 | | 1.38 | |
| OCI | Oakley Capital Investments Limited | 563.0 | 552.0 | 558.0 | 283.7K | 0.0 | | 0.00 | |
| OCN | Ocean Wilsons (Holdings) LD | 1,200 | 1,175 | 1,180 | 33.8K | 0 | | 0.00 | |
| OCTF | First Trust Global Funds Public Limited | 2,018 | 2,018 | 2,018 | 0 | -19 | | 0.92 | |
| OE08 | Bank Of Montreal | 100.4 | 100.4 | 100.4 | 1.0M | 0.0 | | 0.00 | |
| OE61 | The Kingdom Of Morocco | 108.4 | 108.4 | 108.4 | 1.47M | 0.0 | | 0.00 | |
| OFG | Octopus Future Generations Vct PLC | 79.50 | 79.50 | 79.50 | 0 | 0.00 | | 0.00 | |
| OGDC | Oil And Gas Development Company Limited | 8.000 | 8.000 | 8.000 | 0 | 0.000 | | 0.00 | |
| OGG9 | Gold Bullion Securities LD | 330.4 | 321.2 | 321.2 | 3.1K | -10.1 | | 3.04 | |
| OGLD | Deutsche Boerse Commodities Gmbh | 118.2 | 115.8 | 117.7 | 11.7K | 0.3 | | 0.21 | |
| OGN | Origin Enterprises PLC | 3.975 | 3.975 | 3.975 | 97.6K | 0.000 | | 0.00 | |
| OGOL | Global X Metal Securities | 59.26 | 59.26 | 59.26 | 301 | -0.44 | | 0.74 | |
| OGZU | Wisdomtree Metal Securities Limited | 353.3 | 348.1 | 350.3 | 1.5K | 0.1 | | 0.04 | |
| OHGR | One Health Group PLC | 256.0 | 251.0 | 251.0 | 5.3K | 0.0 | | 0.00 | |
| OI20 | Kingdom Of Saudi Arabia (The) | 106.2 | 106.2 | 106.2 | 2.68M | 0.0 | | 0.00 | |
| OIG | Oryx International Growth Fund LTD | 1,221 | 1,206 | 1,220 | 1.4K | 15 | | 1.24 | |
| OIGB | Vaneck Ucits Etfs PLC | 17.67 | 16.84 | 16.84 | 573 | -0.83 | | 4.70 | |
| OIH | Orascom Investment Holding S.A.E | 0.0150 | 0.0140 | 0.0140 | 1.8K | 0.0000 | | 0.00 | |
| OIHV | Vaneck Ucits Etfs PLC | 23.72 | 22.60 | 22.60 | 5.3K | -1.07 | | 4.52 | |
| OIL2 | Wisdomtree Commodity Securities Limited | 605.3 | 578.5 | 578.9 | 1.2K | -28.9 | | 4.75 | |
| OIL3 | UBS AG | 78.24 | 78.24 | 78.24 | 0 | -1.71 | | 2.14 | |
| OILG | UBS AG | 7,173 | 7,173 | 7,173 | 0 | -123 | | 1.69 | |
| OILU | UBS AG | 117.4 | 117.4 | 117.4 | 0 | -2.1 | | 1.76 | |
| OIP9 | Shell International Finance B.V | 98.24 | 98.24 | 98.24 | 300.0K | 0.00 | | 0.00 | |
| OIT | Odyssean Investment Trust PLC | 170.0 | 165.0 | 165.0 | 178.0K | -1.0 | | 0.60 | |
| OM9S | Yorkshire Water Finance PLC | 69.60 | 69.60 | 69.60 | 100.0K | 0.00 | | 0.00 | |
| OMG | Oxford Metrics PLC | 46.90 | 45.10 | 46.50 | 138.8K | 0.45 | | 0.98 | |
| OMI | Orosur Mining INC | 22.40 | 21.00 | 22.00 | 1.25M | 0.00 | | 0.00 | |
| OMIP | One Media Ip Group PLC | 3.750 | 3.750 | 3.750 | 0 | 0.000 | | 0.00 | |
| OMU | Old Mutual Limited | 63.80 | 60.00 | 63.00 | 350.5K | -0.40 | | 0.63 | |
| OMXS | Ishares Iv PLC | 761.8 | 755.0 | 755.0 | 4.2K | -9.6 | | 1.26 | |
| ONDO | Ondo Insurtech PLC | 21.00 | 20.30 | 20.75 | 902.1K | 0.25 | | 1.22 | |
| ONT | Oxford Nanopore Technologies PLC | 127.3 | 121.1 | 125.6 | 1.12M | 2.6 | | 2.11 | |
| ONWD | Onward Opportunities Limited | 141.6 | 140.0 | 141.0 | 39.1K | -1.0 | | 0.70 | |
| OOA | Octopus Aim Vct PLC | 46.60 | 46.60 | 46.60 | 0 | 0.00 | | 0.00 | |
| OPEN | Ishares Iv PLC | 9.992 | 9.937 | 9.937 | 23.4K | -0.028 | | 0.28 | |
| OPG | Opg Power Ventures PLC | 4.550 | 4.100 | 4.250 | 4.54M | -0.140 | | 3.19 | |
| OPT | Optima Health PLC | 195.0 | 192.0 | 193.0 | 236.2K | -2.5 | | 1.28 | |
| OPTI | Optibiotix Health PLC | 6.945 | 6.750 | 6.750 | 5.0K | 0.000 | | 0.00 | |
| OQ12 | Standard Chartered PLC | 92.46 | 92.46 | 92.46 | 0 | 0.00 | | 0.00 | |
| ORC1 | Orchard Bond Finance PLC | 100.0 | 100.0 | 101.0 | 0 | 0.0 | | 0.00 | |
| ORCA | Orcadian Energy PLC | 14.00 | 13.00 | 13.50 | 3.3K | 0.00 | | 0.00 | |
| ORCH | Orchard Funding Group PLC | 60.49 | 60.00 | 60.00 | 8.3K | 0.00 | | 0.00 | |
| ORCP | Oracle Power PLC | 0.0400 | 0.0330 | 0.0380 | 120.54M | 0.0030 | | 8.57 | |
| ORIT | Octopus Renewables Infrastructure Trust | 60.30 | 59.00 | 59.50 | 689.5K | 0.10 | | 0.17 | |
| ORNT | Orient Telecoms PLC | 4.000 | 4.000 | 4.000 | 0 | 0.000 | | 0.00 | |
| ORR | Oriole Resources PLC | 0.3260 | 0.2620 | 0.2800 | 144.36M | -0.0400 | | 12.50 | |
| OS73 | Toyota Finance Australia Limited | 95.00 | 95.00 | 95.00 | 1.0M | 0.00 | | 0.00 | |
| OSB | Osb Group PLC | 605.0 | 593.0 | 601.0 | 693.1K | 5.0 | | 0.84 | |
| OSEC | Octopus Aim Vct 2 PLC | 35.20 | 35.20 | 35.20 | 0 | 0.00 | | 0.00 | |
| OSX5 | Source Markets Public Limited Company | 55.55 | 55.55 | 55.55 | 0 | -0.42 | | 0.75 | |
| OT06 | Derwent London PLC | 72.10 | 72.10 | 72.10 | 9.6K | 0.00 | | 0.00 | |
| OT1 | Oxford Technology 2 Venture Capital | 14.50 | 14.50 | 14.50 | 0 | 0.00 | | 0.00 | |
| OT3 | Oxford Technology 2 Venture Capital | 7.000 | 7.000 | 7.000 | 0 | 0.000 | | 0.00 | |
| OT4 | Oxford Technology 2 Venture Capital | 6.500 | 6.500 | 6.500 | 0 | 0.000 | | 0.00 | |
| OTB | On The Beach Group PLC | 229.5 | 225.0 | 225.5 | 250.6K | -2.0 | | 0.88 | |
| OTES | Hellenic Telecommunications Organization | 9.440 | 9.440 | 9.440 | 8 | 0.000 | | 0.00 | |
| OTPD | Otp Bank PLC | 17.00 | 17.00 | 17.00 | 0 | 0.00 | | 0.00 | |
| OTV2 | Octopus Titan Vct PLC | 24.50 | 24.50 | 24.50 | 0 | 0.00 | | 0.00 | |
| OUFU | Ossiam Irl Icav | 207.1 | 207.1 | 205.2 | 3 | -1.0 | | 0.49 | |
| OVB | Ovoca Bio PLC | 1.295 | 1.045 | 1.150 | 173.3K | 0.000 | | 0.00 | |
| OVCT | Oberon Aim Vct PLC | 25.30 | 25.30 | 25.30 | 0 | 0.00 | | 0.00 | |
| OVZA | Wisdomtree Metal Securities Limited | 144.1 | 133.3 | 143.9 | 992 | 3.6 | | 2.55 | |
| OVZB | Wisdomtree Metal Securities Limited | 125.6 | 121.0 | 125.5 | 100 | 2.6 | | 2.14 | |
| OVZC | Wisdomtree Metal Securities Limited | 49.39 | 48.34 | 49.15 | 23.8K | -0.10 | | 0.19 | |
| OXA1 | Db Etc PLC | 248.4 | 242.3 | 247.4 | 2.1K | -0.8 | | 0.34 | |
| OXA2 | Db Etc PLC | 335.4 | 322.2 | 334.2 | 333 | -2.4 | | 0.71 | |
| OXA5 | Db Etc PLC | 352.5 | 345.0 | 351.3 | 131 | -1.5 | | 0.42 | |
| OXA6 | Db Etc PLC | 506.5 | 501.2 | 505.2 | 100 | 8.0 | | 1.61 | |
| OXB | Oxford Biomedica PLC | 612.0 | 587.0 | 602.0 | 252.0K | -1.0 | | 0.17 | |
| OXH | Oxford Technology 2 Venture Capital | 6.000 | 6.000 | 6.000 | 0 | 0.000 | | 0.00 | |
| OXIG | Oxford Instruments PLC | 2,080 | 2,030 | 2,050 | 228.7K | -15 | | 0.73 | |
| OZ76 | Nationwide Building Society | 98.25 | 98.25 | 98.25 | 578.0K | 0.00 | | 0.00 | |