| Symbol | Bid | Ask | Spread | |
| Icici Bank Ltd | 22.7 | 22.71 | 0.01 | |
| Icon Plc | 213.01 | 213.26 | 0.25 | |
| Iconix Brand Group | 3.12 | 3.16 | 0.04 | |
| Icu Medical | 184.47 | 193.59 | 9.12 | |
| Idacorp Inc | 99.21 | 132.4 | 33.19 | |
| Ideal Power Inc | 10.35 | 10.64 | 0.29 | |
| Identive Group | 6.16 | 8.52 | 2.36 | |
| Idera Pharmaceuticals | 0.425 | 0.425 | 0 | |
| Idex Corp | 204.04 | 208.67 | 4.63 | |
| Idexx Laboratories | 479.32 | 480.2 | 0.88 | |
| IDT Corp | 32.43 | 33.28 | 0.85 | |
| IEC Electronics | 15.22 | 15.29 | 0.07 | |
| If Bancorp Inc | 14.82 | 15.4 | 0.58 | |
| Ifresh Inc | 0.003 | 0.003 | 0 | |
| IHS Markit Ltd | 108.61 | 108.61 | 0 | |
| Ii-Vi Inc | 63.22 | 252.88 | 189.66 | |
| Ikang Healthcare Group Inc | 20.5 | 22.21 | 1.71 | |
| Ikonics Corp | 19.31 | 19.31 | 0 | |
| Illinois Tool Works Inc | 241.51 | 250 | 8.49 | |
| Illumina Inc | 228.82 | 229.16 | 0.34 | |
| Image Sensing Systems | 6.44 | 6.44 | 0 | |
| Imax Corp | 20.95 | 21.5 | 0.55 | |
| Immersion Corp | 8.33 | 9.15 | 0.82 | |
| Immucell Corp | 4.76 | 7.4 | 2.64 | |
| Immune Design Corp | 5.85 | 5.85 | 0 | |
| Immune Pharma Cmn | 0.46 | 0.4679 | 0.0079 | |
| Immunocellular Thera | 0.26 | 0.26 | 0 | |
| Immunogen | 3.85 | 4.43 | 0.58 | |
| Immunomedics | 87.86 | 87.86 | 0 | |
| Impac Mortgage Holdings | 0.26 | 0.2949 | 0.0349 |