steven riley of imperial college.a nobel prize to three physicians on the cure of hepatitis. this is "bloomberg." ♪ so you're a small business, or a big one. you were thriving, but then... oh. ah. okay. plan, pivot. how do you bounce back? you don't, you bounce forward, with serious and reliable internet. powered by the largest gig speed network in america. but is it secure? sure it's secure. and even if the power goes down, your connection doesn't. so how do i do this? you don't do this. we do this, together. bounce forward, with comcast business. tom: this morning, the presidents blood oxygen saturation level rises. stocks as well. markets calm, gold weaker. road trip. mr. trump visits supporters in the hermetically sealed presidential suv . he wants to exit walter reed today. with 29 days until the election, thetrump yearns return to hermetically sealed campaign trail. scheduled10 days to a miami town hall debate. good morning, this is "bloomberg surveillance." .rom new york and london the pandemic in washington. w

steven riley, imperial college london infectious disease.se talk hopkins public health professor. we talk about the midwest in the u.s., four days to the election. that interview at 6:30 a.m. in new york, 10:30 a.m. in london. this is bloomberg. ♪ ritika: this is "bloomberg surveillance." shares of twitter are falling today. the company says it added half new users in the third quarter that analysts expected. expected twitter to see gains from digital sports. 16%,-quarter revenue rose beating estimates. the fastest-growing part of google sought youtube revenue growing 32%. sawbucks better-than-expected quarterly results. same-store sales were down 9%, better than it was in the spring when much of the world was on lockdown. that is your latest bloomberg business flash. tom: thank you so much. now onto tech. i do not want to talk fancy products. i'm to talk financial results. disappointment about the uncertainty forward. alex webb is the bloomberg opinion, in charge of our measurement of uncertainty in technology. involvingn employees trillion

professor steven riley is one of the authors of the react—1 study, and hejoins me now.believe it gives us a more accurate picture than we have had so far. what we've done since early in the spring and through the summer is we select our large random group from the population in england, send eve ryo ne the population in england, send everyone a letter, asking them to ta ke everyone a letter, asking them to take part and we send them a swab whether they have symptoms or not. lots of peoplejoining in, over 850,000 people have taken part across the whole round of the study. then we test those to see if there is coronavirus on the swab. that gives us a picture of, it's independent of... all the different behaviours that contribute to people going to test and trace and things like that so it's a slightly less biased way of looking what is going on in the population. you said you we re on in the population. you said you were disappointed when the data started coming in, why? in our last set of results we saw are turning down in the r number, we saw, the number of infections n