X0306 4 2019-03-29 0 0001394056 ONE STOP SYSTEMS, INC. OSS 0001729652 Ison Jim 2235 ENTERPRISE STREET #110 ESCONDIDO CA 92029 0 1 0 0 Vice President of Sales Common Stock 2019-03-29 4 S 0 9201 2.07 D 3051 D The price reported in column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $2.0128 to $2.081 per share, inclusive. The reporting person undertakes to provide One Stop Systems, Inc., any security holder of One Stop Systems, Inc., or the staff of the Securities and Exchange Commission, upon request, the full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote (1) to this Form 4. /s/Jim Ison 2019-03-29