In the financial-services industry, there are online centers that help brokers to match sellers and buyers of stock based on indications of interest (IOIs). However, at least some of these centers are not only limited in the types of IOIs that they provide, but also in the ways how they allow IOI senders to control IOI usage. Accordingly, to facilitate trades, one exemplary system provides an IOI which is associated with an online negotiation capability. Some versions of this system provide mechanisms for users, such as broker-dealers, to define different IOI response privileges for recipients of their IOIs. To reduce the market risks of failed negotiations, some versions provide automated features for comparing confidential information from traders and initiating online negotiations for stock transactions contingent on favorable comparisons.